diff --git a/target/tencent_cos.lua b/target/tencent_cos.lua
index abd94e9..43bf712 100644
--- a/target/tencent_cos.lua
+++ b/target/tencent_cos.lua
@@ -26,6 +26,9 @@ end
 function tencent_cos:del(appid,endpoint,access_key_id, access_key_secret,bucket_name,object_name)
     return self.module:del(appid,endpoint,access_key_id, access_key_secret,bucket_name,object_name)
 end
+function tencent_cos:exist(appid,endpoint,access_key_id, access_key_secret,bucket_name,object_name)
+    return self.module:exist(appid,endpoint,access_key_id, access_key_secret,bucket_name,object_name)
+end
 function tencent_cos:self()
     return self.module:self()
 end