diff --git a/be/src/runtime/plan_fragment_executor.cpp b/be/src/runtime/plan_fragment_executor.cpp
index 18cfb0d223..0c7c7fb2bd 100644
--- a/be/src/runtime/plan_fragment_executor.cpp
+++ b/be/src/runtime/plan_fragment_executor.cpp
@@ -65,6 +65,11 @@ PlanFragmentExecutor::~PlanFragmentExecutor() {
     // }
     // at this point, the report thread should have been stopped
     DCHECK(!_report_thread_active);
+
+    // fragment mem tracker needs unregister
+    if (_mem_tracker.get() != nullptr) {
+        _mem_tracker->unregister_from_parent();
+    }
 }
 
 Status PlanFragmentExecutor::prepare(const TExecPlanFragmentParams& request) {