diff --git a/api/services/dataset_service.py b/api/services/dataset_service.py
index 4872702a76..3de8f998f4 100644
--- a/api/services/dataset_service.py
+++ b/api/services/dataset_service.py
@@ -10,7 +10,6 @@ from typing import Any, Optional
 
 from flask_login import current_user
 from sqlalchemy import func, select
-from sqlalchemy.orm import Session
 from werkzeug.exceptions import NotFound
 
 from configs import dify_config
@@ -385,13 +384,12 @@ class DatasetService:
             external_knowledge_id: External knowledge identifier
             external_knowledge_api_id: External knowledge API identifier
         """
-        with Session(db.engine) as session:
-            external_knowledge_binding = (
-                session.query(ExternalKnowledgeBindings).filter_by(dataset_id=dataset_id).first()
-            )
+        external_knowledge_binding = (
+            db.session.query(ExternalKnowledgeBindings).filter_by(dataset_id=dataset_id).first()
+        )
 
-            if not external_knowledge_binding:
-                raise ValueError("External knowledge binding not found.")
+        if not external_knowledge_binding:
+            raise ValueError("External knowledge binding not found.")
 
         # Update binding if values have changed
         if (
@@ -400,7 +398,6 @@ class DatasetService:
         ):
             external_knowledge_binding.external_knowledge_id = external_knowledge_id
             external_knowledge_binding.external_knowledge_api_id = external_knowledge_api_id
-            db.session.add(external_knowledge_binding)
 
     @staticmethod
     def _update_internal_dataset(dataset, data, user):
diff --git a/api/tests/unit_tests/services/test_dataset_service_update_dataset.py b/api/tests/unit_tests/services/test_dataset_service_update_dataset.py
index 7c40b1e556..7e0745dcd3 100644
--- a/api/tests/unit_tests/services/test_dataset_service_update_dataset.py
+++ b/api/tests/unit_tests/services/test_dataset_service_update_dataset.py
@@ -118,7 +118,7 @@ class TestDatasetServiceUpdateDataset:
     @pytest.fixture
     def mock_external_provider_dependencies(self):
         """Mock setup for external provider tests."""
-        with patch("services.dataset_service.Session") as mock_session:
+        with patch("sqlalchemy.orm.Session") as mock_session:
             from extensions.ext_database import db
 
             with patch.object(db.__class__, "engine", new_callable=Mock):