diff --git a/api/apps/document_app.py b/api/apps/document_app.py
index 29e168608366293ccf9b04803c053e8f8d5b18d0..033712fd24d7758f19b47e2efbad675d231f9cf7 100644
--- a/api/apps/document_app.py
+++ b/api/apps/document_app.py
@@ -57,7 +57,7 @@ def upload():
         if not e:
             return get_data_error_result(
                 retmsg="Can't find this knowledgebase!")
-        if DocumentService.get_doc_count(kb.tenant_id) >= 128:
+        if DocumentService.get_doc_count(kb.tenant_id) >= os.environ.get('MAX_FILE_NUM_PER_USER', 8192):
             return get_data_error_result(
                 retmsg="Exceed the maximum file number of a free user!")