diff --git a/be/src/olap/data_dir.cpp b/be/src/olap/data_dir.cpp
index a900bbf75594f6..d6f5a974126b06 100755
--- a/be/src/olap/data_dir.cpp
+++ b/be/src/olap/data_dir.cpp
@@ -1068,7 +1068,7 @@ Status DataDir::update_capacity() {
 }
 
 bool DataDir::reach_capacity_limit(int64_t incoming_data_size) {
-    double used_pct = (_available_bytes + incoming_data_size) / (double) _disk_capacity_bytes;
+    double used_pct = (_disk_capacity_bytes - _available_bytes + incoming_data_size) / (double) _disk_capacity_bytes;
     int64_t left_bytes = _disk_capacity_bytes - _available_bytes - incoming_data_size;
     
     if (used_pct >= config::storage_flood_stage_usage_percent / 100.0