diff --git a/benchmarks/backend_request_func.py b/benchmarks/backend_request_func.py
index 0a683dab3..f16db9573 100644
--- a/benchmarks/backend_request_func.py
+++ b/benchmarks/backend_request_func.py
@@ -250,7 +250,7 @@ async def async_request_eb_openai_chat_completions(
                                 # response首token
                                 if res_ttft == 0.0:
                                     if content:
-                                        res_ttft = choices[0]["arrival_time"]
+                                        res_ttft = choices[0].get("arrival_time", timestamp)
                                         output.res_ttft = res_ttft
                                         usage = data.get("usage", {})
                                         output.reasoning_tokens = max(usage.get("completion_tokens", 0) - 1, 0)