diff --git a/src/gausskernel/optimizer/commands/copy.cpp b/src/gausskernel/optimizer/commands/copy.cpp
index e64d5de5a2a1cfa73856e92ebd9926f173667746..5462698639ea5c07c52da5ba39c5a71db6337955 100644
--- a/src/gausskernel/optimizer/commands/copy.cpp
+++ b/src/gausskernel/optimizer/commands/copy.cpp
@@ -1251,7 +1251,8 @@ void VerifyEncoding(int encoding)
 {
     Oid proc;
 
-    if (encoding == GetDatabaseEncoding() || encoding == PG_SQL_ASCII || GetDatabaseEncoding() == PG_SQL_ASCII)
+    if (encoding == GetDatabaseEncoding() || encoding == PG_SQL_ASCII || GetDatabaseEncoding() == PG_SQL_ASCII ||
+        (GetDatabaseEncoding() == PG_GB18030_2022 && encoding == PG_GB18030))
         return;
 
     proc = FindDefaultConversionProc(encoding, GetDatabaseEncoding());