diff --git a/apps/application/flow/step_node/document_split_node/impl/base_document_split_node.py b/apps/application/flow/step_node/document_split_node/impl/base_document_split_node.py
index 508a1986e..80b32f80b 100644
--- a/apps/application/flow/step_node/document_split_node/impl/base_document_split_node.py
+++ b/apps/application/flow/step_node/document_split_node/impl/base_document_split_node.py
@@ -151,9 +151,9 @@ class BaseDocumentSplitNode(IDocumentSplitNode):
                 problem_list.append(document_name)
         elif split_strategy == 'custom':
             if paragraph_title_relate_problem and paragraph.get('title'):
-                problem_list.extend(paragraph.get('title'))
+                problem_list.append(paragraph.get('title'))
             if document_name_relate_problem and document_name:
-                problem_list.extend(document_name)
+                problem_list.append(document_name)
         elif split_strategy == 'qa':
             if document_name_relate_problem and document_name:
                 problem_list.append(document_name)