diff --git a/src/downloadworker.cpp b/src/downloadworker.cpp
index fbece6e..8f38cbe 100644
--- a/src/downloadworker.cpp
+++ b/src/downloadworker.cpp
@@ -100,7 +100,7 @@ DownloadController::DownloadController(QObject *parent)
         "d4.store.deepinos.org.cn",
         "d5.store.deepinos.org.cn"
     };
-    this->threadNum =  domains.size() > 4 ? 4 : domains.size();
+    this->threadNum =  domains.size() > 5 ? 5 : domains.size();
 }
 
 DownloadController::~DownloadController()