diff --git a/src/SJZY.Track.Application/CAP/CAPFilter.cs b/src/SJZY.Track.Application/CAP/CAPFilter.cs
index 6522599b..036c1e34 100644
--- a/src/SJZY.Track.Application/CAP/CAPFilter.cs
+++ b/src/SJZY.Track.Application/CAP/CAPFilter.cs
@@ -30,7 +30,7 @@ public class CapFilter : SubscribeFilter
 
         if (!string.IsNullOrEmpty(argumentJsonStr))
         {
-            var hash = context.DeliverMessage.Headers["sjzy-arguments-hash"];
+            context.DeliverMessage.Headers.TryGetValue("sjzy-arguments-hash", out var hash);
             if (hash.IsNullOrEmpty()) // 计算参数hash
             {
                 hash = GetHash(argumentJsonStr);