diff --git a/api/services/dataset_service.py b/api/services/dataset_service.py
index 1e040abe3e..a3e62544c6 100644
--- a/api/services/dataset_service.py
+++ b/api/services/dataset_service.py
@@ -1416,8 +1416,6 @@ class DocumentService:
         # check document limit
         assert isinstance(current_user, Account)
         assert current_user.current_tenant_id is not None
-        assert knowledge_config.data_source
-        assert knowledge_config.data_source.info_list
 
         features = FeatureService.get_features(current_user.current_tenant_id)
 
@@ -1448,7 +1446,7 @@ class DocumentService:
                     DocumentService.check_documents_upload_quota(count, features)
 
         # if dataset is empty, update dataset data_source_type
-        if not dataset.data_source_type:
+        if not dataset.data_source_type and knowledge_config.data_source:
             dataset.data_source_type = knowledge_config.data_source.info_list.data_source_type
 
         if not dataset.indexing_technique:
@@ -1494,6 +1492,10 @@ class DocumentService:
             documents.append(document)
             batch = document.batch
         else:
+            # When creating new documents, data_source must be provided
+            if not knowledge_config.data_source:
+                raise ValueError("Data source is required when creating new documents")
+
             batch = time.strftime("%Y%m%d%H%M%S") + str(100000 + secrets.randbelow(exclusive_upper_bound=900000))
             # save process rule
             if not dataset_process_rule: