diff --git a/backend/app/subgraphs/contact/nodes.py b/backend/app/subgraphs/contact/nodes.py
index 57c6891..66519c6 100644
--- a/backend/app/subgraphs/contact/nodes.py
+++ b/backend/app/subgraphs/contact/nodes.py
@@ -8,7 +8,7 @@ from typing import Dict, Any
 from datetime import datetime
 
 # 公共工具
-from ..common import MarkdownFormatter
+from app.core import MarkdownFormatter
 
 from .state import ContactState
 from .api_client import ContactAPIClient
diff --git a/backend/app/subgraphs/dictionary/nodes.py b/backend/app/subgraphs/dictionary/nodes.py
index faf06c3..7b76099 100644
--- a/backend/app/subgraphs/dictionary/nodes.py
+++ b/backend/app/subgraphs/dictionary/nodes.py
@@ -8,7 +8,7 @@ from datetime import datetime
 import random
 
 # 公共工具
-from ..common import (
+from app.core import (
     MarkdownFormatter
 )
 
diff --git a/backend/app/subgraphs/news_analysis/nodes.py b/backend/app/subgraphs/news_analysis/nodes.py
index bd8e9d9..fbab16b 100644
--- a/backend/app/subgraphs/news_analysis/nodes.py
+++ b/backend/app/subgraphs/news_analysis/nodes.py
@@ -7,7 +7,7 @@ from typing import Dict, Any
 from datetime import datetime
 
 # 公共工具
-from ..common import MarkdownFormatter
+from app.core import MarkdownFormatter
 
 from .state import (
     NewsAnalysisState,