diff --git a/backend/app/main_graph/nodes/finalize.py b/backend/app/main_graph/nodes/finalize.py
index 420f8b3..5e6af14 100644
--- a/backend/app/main_graph/nodes/finalize.py
+++ b/backend/app/main_graph/nodes/finalize.py
@@ -4,32 +4,23 @@
 """
 
 from typing import Any, Dict
-from app.main_graph.config import get_stream_writer
 
 # 本地模块
-from app.main_graph.state import MessagesState
+from app.main_graph.state import MainGraphState
 from app.utils.logging import log_state_change
-from app.logger import info, error
+from app.logger import info, warning
 
 from langchain_core.runnables.config import RunnableConfig
 
 
-def _get_attr(state, attr_name, default=None):
-    """通用方法：兼容 dict 和 dataclass 两种状态格式"""
-    if isinstance(state, dict):
-        return state.get(attr_name, default)
-    else:
-        return getattr(state, attr_name, default)
-
-
-async def finalize_node(state, config: RunnableConfig) -> Dict[str, Any]:
+async def finalize_node(state: MainGraphState, config: RunnableConfig) -> Dict[str, Any]:
     """
     完成事件节点 - 发送完成事件，包含token使用情况和耗时信息
-    
+
     Args:
-        state: 当前对话状态（兼容 dict 和 dataclass）
+        state: 当前对话状态
         config: 运行时配置
-    
+
     Returns:
         空字典（完成节点，无状态更新）
     """
@@ -37,18 +28,25 @@ async def finalize_node(state, config: RunnableConfig) -> Dict[str, Any]:
 
     try:
         # 获取流式写入器并发送完成事件
+        from app.main_graph.config import get_stream_writer
         writer = get_stream_writer()
-        writer({
-            "type": "custom", 
-            "data": {
-                "type": "done",
-                "token_usage": _get_attr(state, "last_token_usage", {}),
-                "elapsed_time": _get_attr(state, "last_elapsed_time", 0.0)
-            }
-        })
-        info("🏁 [完成事件] 已发送完成事件，包含token使用情况和耗时信息")
+        
+        # 只在 writer 存在且不是 noop 时才发送
+        if writer and hasattr(writer, '__call__'):
+            try:
+                writer({
+                    "type": "custom", 
+                    "data": {
+                        "type": "done",
+                        "token_usage": state.last_token_usage,
+                        "elapsed_time": state.last_elapsed_time
+                    }
+                })
+                info("🏁 [完成事件] 已发送完成事件，包含token使用情况和耗时信息")
+            except Exception as e:
+                warning(f"⚠️ [完成事件] 发送完成事件失败 (非致命): {e}")
     except Exception as e:
-        error(f"❌ [完成事件] 发送完成事件时发生异常: {e}")
+        warning(f"⚠️ [完成事件] 处理失败 (非致命): {e}")
     
     log_state_change("finalize", state, "离开")
     return {}
\ No newline at end of file
diff --git a/backend/app/main_graph/nodes/memory_trigger.py b/backend/app/main_graph/nodes/memory_trigger.py
index c8afcf0..e848559 100644
--- a/backend/app/main_graph/nodes/memory_trigger.py
+++ b/backend/app/main_graph/nodes/memory_trigger.py
@@ -1,18 +1,10 @@
 from typing import Any, Dict
 from langchain_core.runnables.config import RunnableConfig
-from app.main_graph.state import MessagesState
+from app.main_graph.state import MainGraphState
 from app.memory.mem0_client import Mem0Client
 from app.logger import info
 
 
-def _get_attr(state, attr_name, default=None):
-    """通用方法：兼容 dict 和 dataclass 两种状态格式"""
-    if isinstance(state, dict):
-        return state.get(attr_name, default)
-    else:
-        return getattr(state, attr_name, default)
-
-
 # 全局变量，在 GraphBuilder 中注入
 _mem0_client: Mem0Client = None
 
@@ -22,12 +14,12 @@ def set_mem0_client(client: Mem0Client):
     _mem0_client = client
 
 
-async def memory_trigger_node(state, config: RunnableConfig) -> Dict[str, Any]:
+async def memory_trigger_node(state: MainGraphState, config: RunnableConfig) -> Dict[str, Any]:
     """检测用户消息中的记忆指令，若命中则主动调用 Mem0 存储"""
     if _mem0_client is None:
         return {}
 
-    messages = _get_attr(state, "messages", [])
+    messages = state.messages
     if not messages:
         return {}
 
diff --git a/backend/app/main_graph/nodes/retrieve_memory.py b/backend/app/main_graph/nodes/retrieve_memory.py
index 3aac9fd..ed8b4fa 100644
--- a/backend/app/main_graph/nodes/retrieve_memory.py
+++ b/backend/app/main_graph/nodes/retrieve_memory.py
@@ -6,20 +6,12 @@
 from typing import Any, Dict
 
 # 本地模块
-from app.main_graph.state import MessagesState
+from app.main_graph.state import MainGraphState
 from app.memory.mem0_client import Mem0Client
 from app.utils.logging import log_state_change
 from app.logger import debug
 
 
-def _get_attr(state, attr_name, default=None):
-    """通用方法：兼容 dict 和 dataclass 两种状态格式"""
-    if isinstance(state, dict):
-        return state.get(attr_name, default)
-    else:
-        return getattr(state, attr_name, default)
-
-
 def create_retrieve_memory_node(mem0_client: Mem0Client):
     """
     工厂函数：创建记忆检索节点
@@ -33,12 +25,12 @@ def create_retrieve_memory_node(mem0_client: Mem0Client):
     
     from langchain_core.runnables.config import RunnableConfig
     
-    async def retrieve_memory(state, config: RunnableConfig) -> Dict[str, Any]:
+    async def retrieve_memory(state: MainGraphState, config: RunnableConfig) -> Dict[str, Any]:
         """
         记忆检索节点 - 使用 Mem0
         
         Args:
-            state: 当前对话状态（兼容 dict 和 dataclass）
+            state: 当前对话状态
             config: 运行时配置
         
         Returns:
@@ -49,16 +41,16 @@ def create_retrieve_memory_node(mem0_client: Mem0Client):
         # 从 metadata 中获取 user_id
         user_id = config.get("metadata", {}).get("user_id", "default_user")
         
-        # 兼容 dict 和对象两种消息格式
-        messages = _get_attr(state, "messages", [])
+        # 获取最后一条消息
+        messages = state.messages
         last_msg = messages[-1] if messages else None
+        query = ""
         if last_msg:
             if isinstance(last_msg, dict):
                 query = str(last_msg.get("content", ""))
             else:
                 query = str(last_msg.content)
-        else:
-            query = ""
+        
         memory_text_parts = []
 
         # 确保 Mem0 已初始化（懒加载）
@@ -83,7 +75,7 @@ def create_retrieve_memory_node(mem0_client: Mem0Client):
 
         memory_context = "\n\n".join(memory_text_parts) if memory_text_parts else "暂无用户信息"
         result = {"memory_context": memory_context}
-        log_state_change("retrieve_memory", {**state, **result} if isinstance(state, dict) else state, "离开")
+        log_state_change("retrieve_memory", state, "离开")
         return result
     
     return retrieve_memory
\ No newline at end of file
diff --git a/backend/app/main_graph/nodes/summarize.py b/backend/app/main_graph/nodes/summarize.py
index f817266..d75ba1d 100644
--- a/backend/app/main_graph/nodes/summarize.py
+++ b/backend/app/main_graph/nodes/summarize.py
@@ -6,20 +6,12 @@
 from typing import Any, Dict
 
 # 本地模块
-from app.main_graph.state import MessagesState
+from app.main_graph.state import MainGraphState
 from app.memory.mem0_client import Mem0Client
 from app.utils.logging import log_state_change
 from app.logger import debug, info, error, warning
 
 
-def _get_attr(state, attr_name, default=None):
-    """通用方法：兼容 dict 和 dataclass 两种状态格式"""
-    if isinstance(state, dict):
-        return state.get(attr_name, default)
-    else:
-        return getattr(state, attr_name, default)
-
-
 def create_summarize_node(mem0_client: Mem0Client):
     """
     工厂函数：创建记忆存储节点
@@ -33,12 +25,12 @@ def create_summarize_node(mem0_client: Mem0Client):
     
     from langchain_core.runnables.config import RunnableConfig
     
-    async def summarize_conversation(state, config: RunnableConfig) -> Dict[str, Any]:
+    async def summarize_conversation(state: MainGraphState, config: RunnableConfig) -> Dict[str, Any]:
         """
         记忆存储节点 - 使用 Mem0
         
         Args:
-            state: 当前对话状态（兼容 dict 和 dataclass）
+            state: 当前对话状态
             config: 运行时配置
         
         Returns:
@@ -46,7 +38,7 @@ def create_summarize_node(mem0_client: Mem0Client):
         """
         log_state_change("summarize", state, "进入")
 
-        messages = _get_attr(state, "messages", [])
+        messages = state.messages
         if len(messages) < 4:
             debug("📝 [记忆添加] 对话过短，跳过")
             return {"turns_since_last_summary": 0}
diff --git a/backend/app/main_graph/state.py b/backend/app/main_graph/state.py
index 182ece8..8450f20 100644
--- a/backend/app/main_graph/state.py
+++ b/backend/app/main_graph/state.py
@@ -10,17 +10,9 @@ from app.main_graph.graph import add_messages
 from langchain_core.messages import BaseMessage
 
 
-# ========== 兼容旧代码的类型 ==========
-class MessagesState(TypedDict):
-    """旧的MessagesState类型（保留兼容性）"""
-    messages: Annotated[Sequence[BaseMessage], add_messages]
-
-
-class GraphContext(TypedDict):
-    """旧的GraphContext类型（保留兼容性）"""
-    llm_calls: int
-    memory_context: str
-    system_prompt: str
+# ========== 兼容性注释（旧代码已移除，状态已整合到 MainGraphState） ==========
+# 旧的 MessagesState 和 GraphContext 已完全整合到 MainGraphState
+# 不再需要单独的类型定义
 
 
 # ========== 新的类型 ==========
@@ -57,49 +49,52 @@ class ErrorRecord:
 @dataclass
 class MainGraphState:
     """
-    主图状态 - React 循环推理版本
+    主图状态 - 整合了旧 MessagesState 的所有字段
     
     包含：
-    1. 旧代码的MessagesState兼容性字段
-    2. React 推理控制字段
-    3. 循环和错误处理
-    4. 子图结果占位
-    5. 用户信息
+    - 旧代码的 MessagesState 兼容性字段
+    - React 推理控制字段
+    - 循环和错误处理
+    - 子图结果占位
+    - 用户信息
     """
-    # ========== 兼容性字段（保留旧的MessagesState） ==========
+    # ========== 旧 MessagesState 兼容性字段 ==========
     messages: Annotated[Sequence[BaseMessage], add_messages] = field(default_factory=list)
     llm_calls: int = 0
     memory_context: str = ""
     system_prompt: str = ""
+    turns_since_last_summary: int = 0  # 新增：来自旧状态
+    last_token_usage: Dict[str, Any] = field(default_factory=dict)  # 新增：来自旧状态
+    last_elapsed_time: float = 0.0  # 新增：来自旧状态
     
     # ========== 主图控制字段 ==========
-    user_query: str = ""  # 用户当前查询
-    current_action: CurrentAction = CurrentAction.NONE  # 当前操作
-    intent_confidence: float = 0.0  # 意图识别置信度
+    user_query: str = ""
+    current_action: CurrentAction = CurrentAction.NONE
+    intent_confidence: float = 0.0
     
     # ========== React 推理专用字段 ==========
-    reasoning_step: int = 0  # 当前推理步数
-    max_steps: int = 40  # 最大推理步数
-    last_action: str = ""  # 上一步动作
-    reasoning_history: List[Dict[str, Any]] = field(default_factory=list)  # 推理历史
+    reasoning_step: int = 0
+    max_steps: int = 40
+    last_action: str = ""
+    reasoning_history: List[Dict[str, Any]] = field(default_factory=list)
     
     # ========== RAG 相关字段 ==========
-    rag_context: str = ""  # RAG 检索到的上下文
-    rag_retrieved: bool = False  # 是否已经检索过
-    rag_docs: List[Dict[str, Any]] = field(default_factory=list)  # 检索到的文档
+    rag_context: str = ""
+    rag_retrieved: bool = False
+    rag_docs: List[Dict[str, Any]] = field(default_factory=list)
     
-    # ========== 联网搜索相关字段 ⭐ 新增 ==========
-    web_search_results: List[str] = field(default_factory=list)  # 联网搜索结果
+    # ========== 联网搜索相关字段 ==========
+    web_search_results: List[str] = field(default_factory=list)
     
     # ========== 错误处理字段 ==========
-    errors: List[ErrorRecord] = field(default_factory=list)  # 错误列表
-    current_error: Optional[ErrorRecord] = None  # 当前错误
-    retry_action: Optional[str] = None  # 重试动作
+    errors: List[ErrorRecord] = field(default_factory=list)
+    current_error: Optional[ErrorRecord] = None
+    retry_action: Optional[str] = None
     
     # ========== 子图结果占位 ==========
-    news_result: Optional[Dict[str, Any]] = None  # 资讯子图结果
-    dictionary_result: Optional[Dict[str, Any]] = None  # 词典子图结果
-    contact_result: Optional[Dict[str, Any]] = None  # 通讯录子图结果
+    news_result: Optional[Dict[str, Any]] = None
+    dictionary_result: Optional[Dict[str, Any]] = None
+    contact_result: Optional[Dict[str, Any]] = None
     
     # ========== 用户信息 ==========
     user_id: str = ""
diff --git a/backend/app/main_graph/utils/main_graph_builder.py b/backend/app/main_graph/utils/main_graph_builder.py
index eb51760..ab391b0 100644
--- a/backend/app/main_graph/utils/main_graph_builder.py
+++ b/backend/app/main_graph/utils/main_graph_builder.py
@@ -1,13 +1,12 @@
 """
-整合后的完整主图构建器 - 结合旧图和新图的优点
-Main Graph Builder - Integrated Full Version (Old + New)
+整合后的完整主图构建器 - 所有节点都直接操作 MainGraphState
 """
 
 from app.main_graph.graph import StateGraph, START, END
 from typing import Dict, Any, Optional
 from langchain_core.runnables.config import RunnableConfig
 
-from app.main_graph.state import MainGraphState, CurrentAction, MessagesState
+from app.main_graph.state import MainGraphState
 from app.main_graph.nodes.react_nodes import (
     init_state_node,
     react_reason_node,
@@ -28,16 +27,21 @@ from app.memory.mem0_client import Mem0Client
 from app.logger import info, debug
 
 
-# ========== 全局变量（用于传递 mem0_client）==========
-# 这样就不用改旧节点的签名了
-_global_mem0_client: Optional[Mem0Client] = None
-
-
-def set_global_mem0_client(client: Mem0Client):
-    """设置全局的 mem0_client"""
-    global _global_mem0_client
-    _global_mem0_client = client
-    set_mem0_client(client)  # 同时设置给 memory_trigger_node
+# ========== 检查是否需要总结 ==========
+def should_summarize(state: MainGraphState) -> str:
+    """
+    检查是否需要总结对话（对话足够长时）
+    
+    Args:
+        state: 当前图状态
+    
+    Returns:
+        "summarize" 或 "finalize"
+    """
+    if state.turns_since_last_summary >= 5:  # 每5轮对话总结一次
+        return "summarize"
+    else:
+        return "finalize"
 
 
 # ========== 子图包装器（处理子图错误传递）==========
@@ -93,65 +97,18 @@ def wrap_subgraph_for_error_handling(subgraph, name: str):
     return wrapped_node
 
 
-# ========== 检查是否需要总结 ==========
-def should_summarize(state: MainGraphState) -> str:
-    """
-    检查是否需要总结对话（对话足够长时）
-    
-    Args:
-        state: 当前图状态
-    
-    Returns:
-        "summarize" 或 "finalize"
-    """
-    messages = getattr(state, 'messages', [])
-    if len(messages) >= 4:
-        return "summarize"
-    else:
-        return "finalize"
-
-
-# ========== 兼容层：让旧节点工作在新状态上 ==========
-def adapt_old_node_for_new_state(old_node):
-    """
-    适配旧节点（期望 MessagesState）到新状态 MainGraphState
-    
-    Args:
-        old_node: 旧节点函数
-    
-    Returns: 适配后的节点函数
-    """
-    async def adapted_node(state: MainGraphState, config: RunnableConfig) -> Dict[str, Any]:
-        # 把 MainGraphState 转换为 MessagesState（旧节点期望的格式）
-        old_state: MessagesState = {
-            "messages": state.messages,
-            "llm_calls": getattr(state, 'llm_calls', 0),
-            "memory_context": getattr(state, 'memory_context', ""),
-            "system_prompt": getattr(state, 'system_prompt', "")
-        }
-        
-        # 调用旧节点
-        result = await old_node(old_state, config)
-        
-        # 把结果更新回 MainGraphState
-        if "memory_context" in result:
-            state.memory_context = result["memory_context"]
-        if "llm_calls" in result:
-            state.llm_calls = result["llm_calls"]
-        
-        return result
-    
-    return adapted_node
-
-
 # ========== 主图构建 ==========
 def build_react_main_graph(llm=None, tools=None, mem0_client=None) -> StateGraph:
     """
-    构建整合后的完整主图（简化版：先让系统工作起来）
+    构建整合后的完整主图
     
     完整流程：
     START
       ↓
+    retrieve_memory (从Mem0检索长期记忆)
+      ↓
+    memory_trigger (记忆触发器)
+      ↓
     init_state (初始化)
       ↓
     react_reason (推理) ←───────────────────────┐
@@ -165,6 +122,10 @@ def build_react_main_graph(llm=None, tools=None, mem0_client=None) -> StateGraph
       ├─ handle_error → (重试或结束) ────────────┤
       └─ llm_call (大模型调用) ←────────────────┘
            ↓
+    检查：需要总结吗？
+      ├─ 是 → summarize (提交给Mem0存储)
+      └─ 否 → (跳过)
+           ↓
     finalize (发送完成事件)
       ↓
     END
@@ -172,7 +133,7 @@ def build_react_main_graph(llm=None, tools=None, mem0_client=None) -> StateGraph
     # 创建图
     graph = StateGraph(MainGraphState)
     
-    # 设置全局 mem0_client (暂时不用记忆功能)
+    # 设置全局 mem0_client
     if mem0_client:
         set_global_mem0_client(mem0_client)
     
@@ -181,8 +142,20 @@ def build_react_main_graph(llm=None, tools=None, mem0_client=None) -> StateGraph
     if llm is not None:
         llm_node = create_llm_call_node(llm, tools or [])
     
+    retrieve_memory_node = None
+    summarize_node = None
+    if mem0_client:
+        retrieve_memory_node = create_retrieve_memory_node(mem0_client)
+        summarize_node = create_summarize_node(mem0_client)
+    
     # ========== 添加节点 ==========
-    # 简化：先不用记忆检索相关节点
+    
+    # 第一阶段：记忆检索
+    if retrieve_memory_node:
+        graph.add_node("retrieve_memory", retrieve_memory_node)
+    graph.add_node("memory_trigger", memory_trigger_node)
+    
+    # 第二阶段：React 循环推理
     graph.add_node("init_state", init_state_node)
     graph.add_node("react_reason", react_reason_node)
     graph.add_node("rag_retrieve", rag_retrieve_node)
@@ -210,15 +183,25 @@ def build_react_main_graph(llm=None, tools=None, mem0_client=None) -> StateGraph
         wrap_subgraph_for_error_handling(news_analysis_graph.compile(), "news_analysis")
     )
     
-    # 完成节点
+    # 第三阶段：完成处理
+    if summarize_node:
+        graph.add_node("summarize", summarize_node)
     graph.add_node("finalize", finalize_node)
     
     # ========== 添加边 ==========
-    # 简化：直接从 START 到 init_state
-    graph.add_edge(START, "init_state")
+    
+    # 第一阶段：记忆检索
+    if retrieve_memory_node:
+        graph.add_edge(START, "retrieve_memory")
+        graph.add_edge("retrieve_memory", "memory_trigger")
+    else:
+        graph.add_edge(START, "memory_trigger")
+    
+    # 进入第二阶段
+    graph.add_edge("memory_trigger", "init_state")
     graph.add_edge("init_state", "react_reason")
     
-    # 条件路由
+    # 第二阶段：React 循环推理
     graph.add_conditional_edges(
         "react_reason",
         route_by_reasoning,
@@ -241,14 +224,27 @@ def build_react_main_graph(llm=None, tools=None, mem0_client=None) -> StateGraph
     graph.add_edge("news_analysis_subgraph", "react_reason")
     graph.add_edge("handle_error", "react_reason")
     
-    # llm_call 之后直接到 finalize
+    # 第三阶段：llm_call 后进入完成处理
     if llm_node is not None:
-        graph.add_edge("llm_call", "finalize")
+        if summarize_node:
+            # 检查是否需要总结
+            graph.add_conditional_edges(
+                "llm_call",
+                should_summarize,
+                {
+                    "summarize": "summarize",
+                    "finalize": "finalize"
+                }
+            )
+            graph.add_edge("summarize", "finalize")
+        else:
+            # 没有 summarize 节点，直接 finalize
+            graph.add_edge("llm_call", "finalize")
     
     # 完成
     graph.add_edge("finalize", END)
     
-    info("✅ [图构建] 整合后的完整主图构建完成（简化版）")
+    info("✅ [图构建] 整合后的完整主图构建完成")
     
     return graph
 
@@ -265,6 +261,5 @@ def build_main_graph() -> StateGraph:
 __all__ = [
     "build_react_main_graph",
     "build_main_graph",
-    "wrap_subgraph_for_error_handling",
-    "set_global_mem0_client"
-]
+    "wrap_subgraph_for_error_handling"
+]
\ No newline at end of file
diff --git a/backend/app/utils/logging.py b/backend/app/utils/logging.py
index 770c731..c3137fc 100644
--- a/backend/app/utils/logging.py
+++ b/backend/app/utils/logging.py
@@ -7,14 +7,6 @@ from app.config import ENABLE_GRAPH_TRACE
 from app.logger import debug, info
 
 
-def _get_attr(state, attr_name, default=None):
-    """通用方法：兼容 dict 和 dataclass 两种状态格式"""
-    if isinstance(state, dict):
-        return state.get(attr_name, default)
-    else:
-        return getattr(state, attr_name, default)
-
-
 def log_state_change(node_name: str, state, prefix: str = "进入"):
     """
     记录状态变化日志
@@ -26,7 +18,13 @@ def log_state_change(node_name: str, state, prefix: str = "进入"):
     """
     from app.logger import info
     
-    messages = _get_attr(state, "messages", [])
+    # 获取 messages
+    messages = []
+    if isinstance(state, dict):
+        messages = state.get("messages", [])
+    else:
+        messages = getattr(state, "messages", [])
+    
     msg_count = len(messages)
     last_msg = messages[-1] if messages else None
     last_info = ""
@@ -48,7 +46,7 @@ def print_llm_input(prompt_value):
     
     Args:
         prompt_value: ChatPromptValue 对象，包含格式化后的消息列表
-        
+    
     Returns:
         原样返回 prompt_value，不影响链式调用
     """
@@ -56,14 +54,14 @@ def print_llm_input(prompt_value):
         return prompt_value
 
     messages = prompt_value.messages  # ChatPromptValue 提供 .messages 属性
-
-    debug("\n" + "=" * 80)
-    debug("📤 [LLM输入] 格式化后发送给大模型的完整消息:")
+    
+    debug("\n" + "="*80)
+    debug("📥 [LLM输入] 格式化后发送给大模型的完整消息:")
     debug(f"   总消息数: {len(messages)}")
-    debug("-" * 80)
+    debug("-"*80)
     for i, msg in enumerate(messages):
         content_preview = str(msg.content)  # 完整输出
         debug(f"   [{i}] {msg.type.upper():10s}: {content_preview}")
-    debug("\n" + "=" * 80 + "\n")
+    debug("\n" + "="*80 + "\n")
 
-    return prompt_value
+    return prompt_value
\ No newline at end of file