diff --git a/frameworks/native/backup_ext/src/ext_extension.cpp b/frameworks/native/backup_ext/src/ext_extension.cpp
index a5dd1cfd3aa9f29a9c83dfa08031ee1675bd7d78..1119285af81d4ed82d7d34ba1f241f1681813c15 100644
--- a/frameworks/native/backup_ext/src/ext_extension.cpp
+++ b/frameworks/native/backup_ext/src/ext_extension.cpp
@@ -1004,7 +1004,7 @@ void BackupExtExtension::AsyncTaskBackup(const string config)
             if (!ptr->StopExtTimer()) {
                 throw BError(BError::Codes::EXT_TIMER_ERROR, "Failed to stop extTimer");
             }
-            int64_t totalSize;
+            int64_t totalSize = 0;
             TarMap bigFileInfo;
             map<string, size_t> smallFiles;
             BJsonCachedEntity<BJsonEntityExtensionConfig> cachedEntity(config);