diff --git a/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Managers/AiGateWayManager.cs b/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Managers/AiGateWayManager.cs
index 3206ee64..4b2b2475 100644
--- a/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Managers/AiGateWayManager.cs
+++ b/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Managers/AiGateWayManager.cs
@@ -132,7 +132,7 @@ public class AiGateWayManager : DomainService
             await _aiMessageManager.CreateSystemMessageAsync(userId.Value, sessionId,
                 new MessageInputDto
                 {
-                    Content = data.Choices.FirstOrDefault()?.Delta.Content,
+                    Content = data.Choices?.FirstOrDefault()?.Delta.Content,
                     ModelId = request.Model,
                     TokenUsage = data.Usage
                 });