diff --git a/csst_dfs_api_cluster/common/catalog.py b/csst_dfs_api_cluster/common/catalog.py
index 5caec09967a42761fb08ce50992d18b99ec57bfb..65f97cdab3c9612c71640159bcca7e8f8e9ead28 100644
--- a/csst_dfs_api_cluster/common/catalog.py
+++ b/csst_dfs_api_cluster/common/catalog.py
@@ -2,7 +2,6 @@ import grpc
 import pickle
 from collections import deque
 import logging
-import zlib
 import io
 
 from csst_dfs_commons.models import Result
@@ -51,7 +50,7 @@ class CatalogApi(object):
                 else:
                     return Result.error(message = str(resp.error.detail))
             datas.flush()
-            records = pickle.loads(zlib.decompress(datas.getvalue()))
+            records = pickle.loads(datas.getvalue())
             ret_records2 = []
             for r in records:
                 rec = Gaia3Record()