diff --git a/backend/app/config.py b/backend/app/config.py
index b62f05e..4705d43 100644
--- a/backend/app/config.py
+++ b/backend/app/config.py
@@ -7,7 +7,9 @@
 """
 
 import os
+from dotenv import load_dotenv
 
+load_dotenv()
 
 # ========== 辅助函数：类型转换 ==========
 def _get_str(key: str) -> str | None:
diff --git a/backend/app/graph/visualize_graph.py b/backend/app/graph/visualize_graph.py
new file mode 100644
index 0000000..83d1f13
--- /dev/null
+++ b/backend/app/graph/visualize_graph.py
@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+"""
+LangGraph 图结构可视化脚本
+快速查看节点和边的连接关系
+
+================================================================================
+运行方式（推荐用第一种）：
+================================================================================
+
+方式 1: 从项目根目录直接运行脚本（推荐，最稳定）
+----------------------------------------------------------------------
+cd /home/huang/Study/AIProject/Agent1
+python backend/app/graph/visualize_graph.py
+
+方式 2: 如果非要用模块方式运行，需要先设置 PYTHONPATH
+----------------------------------------------------------------------
+cd /home/huang/Study/AIProject/Agent1
+export PYTHONPATH=/home/huang/Study/AIProject/Agent1/backend:$PYTHONPATH
+python -m backend.app.graph.visualize_graph
+================================================================================
+"""
+import sys
+from pathlib import Path
+from dotenv import load_dotenv
+
+# 确定项目根目录（Agent1 目录）
+# 当前文件位置：backend/app/graph/visualize_graph.py
+# 向上 4 级到 Agent1
+PROJECT_ROOT = Path(__file__).parent.parent.parent.parent
+BACKEND_DIR = PROJECT_ROOT / "backend"
+
+# 关键：把 backend 目录加入 sys.path，这样才能找到 rag_core
+# 注意：这只对直接运行脚本有效，对 -m 方式无效（因为 -m 方式在脚本运行前就导入了）
+if str(BACKEND_DIR) not in sys.path:
+    sys.path.insert(0, str(BACKEND_DIR))
+if str(PROJECT_ROOT) not in sys.path:
+    sys.path.insert(0, str(PROJECT_ROOT))
+
+load_dotenv(PROJECT_ROOT / ".env")
+
+from app.agent.service import AIAgentService
+from app.config import DB_URI
+from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
+import asyncio
+
+
+async def visualize_graph():
+    """可视化 LangGraph 结构"""
+    print("=" * 80)
+    print("  LangGraph 图结构可视化")
+    print("=" * 80)
+    print(f"项目根目录: {PROJECT_ROOT}")
+    print(f"Backend 目录: {BACKEND_DIR}")
+
+    async with AsyncPostgresSaver.from_conn_string(DB_URI) as checkpointer:
+        await checkpointer.setup()
+
+        # 创建服务实例
+        print("\n正在初始化 Agent 服务...")
+        agent_service = AIAgentService(checkpointer)
+        await agent_service.initialize()
+
+        for model_name, graph in agent_service.graphs.items():
+            print(f"\n{'=' * 80}")
+            print(f"  模型: {model_name}")
+            print(f"{'=' * 80}")
+
+            # 获取图结构
+            graph_structure = graph.get_graph()
+
+            # 1. 直接打印节点和边
+            print("\n[1] 节点列表:")
+            print("-" * 80)
+            for node_id, node in graph_structure.nodes.items():
+                print(f"  - {node_id}: {node.name}")
+
+            print("\n[2] 边列表:")
+            print("-" * 80)
+            for edge in graph_structure.edges:
+                print(f"  {edge.source} --> {edge.target}")
+
+            # 3. ASCII 字符画（需要 grandalf）
+            print("\n[3] ASCII 字符画:")
+            print("-" * 80)
+            try:
+                print(graph_structure.draw_ascii())
+            except Exception as e:
+                print(f"⚠️  ASCII 绘制失败: {e}")
+
+            # 4. Mermaid 源码
+            print("\n[4] Mermaid 源码 (可复制到 https://mermaid.live/):")
+            print("-" * 80)
+            print(graph_structure.draw_mermaid())
+
+
+if __name__ == "__main__":
+    asyncio.run(visualize_graph())
diff --git a/backend/app/logger.py b/backend/app/logger.py
index 777aeec..8b263c6 100644
--- a/backend/app/logger.py
+++ b/backend/app/logger.py
@@ -7,14 +7,6 @@ import os
 from .config import LOG_LEVEL, DEBUG
 import logging
 from typing import Any
-from dotenv import load_dotenv
-
-# 先加载环境变量
-load_dotenv()
-
-# 从环境变量读取日志级别，默认 INFO
-
-
 # 根据环境变量控制是否显示详细调试信息
 DEBUG_MODE = DEBUG