diff --git a/swift/llm/deploy.py b/swift/llm/deploy.py
index a905bab5e..438c87a3a 100644
--- a/swift/llm/deploy.py
+++ b/swift/llm/deploy.py
@@ -420,10 +420,10 @@ async def _generate_stream():
                     choices.append(choice)
                 response = CompletionStreamResponse(
                     model=request.model, choices=choices, usage=usage_info, id=request_id, created=created_time)
-            yield f'data:{json.dumps(asdict(response), ensure_ascii=False)}\n\n'
+            yield f'data: {json.dumps(asdict(response), ensure_ascii=False)}\n\n'
         if _args.log_interval > 0:
             _update_stats(response)
-        yield 'data:[DONE]\n\n'
+        yield 'data: [DONE]\n\n'
 
     if request.stream:
         return StreamingResponse(_generate_stream())
@@ -599,10 +599,10 @@ async def _generate_stream():
                     choices = [CompletionResponseStreamChoice(index=0, text=delta_text, finish_reason=finish_reason)]
                     response = CompletionStreamResponse(
                         model=request.model, choices=choices, usage=usage_info, id=request_id, created=created_time)
-                yield f'data:{json.dumps(asdict(response), ensure_ascii=False)}\n\n'
+                yield f'data: {json.dumps(asdict(response), ensure_ascii=False)}\n\n'
             if _args.log_interval > 0:
                 _update_stats(response)
-            yield 'data:[DONE]\n\n'
+            yield 'data: [DONE]\n\n'
 
     if request.stream:
         return StreamingResponse(_generate_stream())
@@ -827,10 +827,10 @@ def _generate_stream():
                 choices = [CompletionResponseStreamChoice(index=0, text=delta_text, finish_reason=None)]
                 resp = CompletionStreamResponse(
                     model=request.model, choices=choices, usage=usage_info, id=request_id, created=created_time)
-            yield f'data:{json.dumps(asdict(resp), ensure_ascii=False)}\n\n'
+            yield f'data: {json.dumps(asdict(resp), ensure_ascii=False)}\n\n'
         if _args.log_interval > 0:
             _update_stats(resp)
-        yield 'data:[DONE]\n\n'
+        yield 'data: [DONE]\n\n'
 
     if request.stream:
         return StreamingResponse(_generate_stream())
diff --git a/swift/llm/utils/client_utils.py b/swift/llm/utils/client_utils.py
index 05978cd5c..c718c2066 100644
--- a/swift/llm/utils/client_utils.py
+++ b/swift/llm/utils/client_utils.py
@@ -58,8 +58,8 @@ def _parse_stream_data(data: bytes) -> Optional[str]:
     data = data.strip()
     if len(data) == 0:
         return
-    assert data.startswith('data:'), f'data: {data}'
-    return data[5:].strip()
+    assert data.startswith('data: '), f'data: {data}'
+    return data[6:].strip()
 
 
 def _to_base64(img_path: Union[str, 'PIL.Image.Image', bytes]) -> str: