diff --git a/src/obproxy/proxy/mysqllib/ob_proxy_session_info_handler.cpp b/src/obproxy/proxy/mysqllib/ob_proxy_session_info_handler.cpp
index 4862018b8ab5b5333f6b9d0fb6799ac03e00f38e..01f799b4e8eb6d09b347148bcdf19c404ababdf2 100644
--- a/src/obproxy/proxy/mysqllib/ob_proxy_session_info_handler.cpp
+++ b/src/obproxy/proxy/mysqllib/ob_proxy_session_info_handler.cpp
@@ -220,11 +220,8 @@ int ObProxySessionInfoHandler::rewrite_login_req_by_sharding(ObClientSessionInfo
       LOG_WARN("fail to encrypt_passwd_to_stage1", K(ret));
     } else {
       passwd_string += 1;
-      OMPKHandshake handshake;
       int64_t actual_len = 0;
-      char scramble_buf[SCRAMBLE_LENGTH + 1] = {0};
-      handshake.get_scramble(scramble_buf, SCRAMBLE_LENGTH + 1, actual_len);
-      ObString scramble_string(actual_len, scramble_buf);
+      const ObString &scramble_string = client_info.get_scramble_string();
       if (OB_FAIL(ObClientUtils::get_auth_password_from_stage1(passwd_string,
               scramble_string, pwd_buf, pwd_buf_len, actual_len))) {
             LOG_WARN("fail to get get_auth_password_from_stage1", K(ret));