diff --git a/fastdeploy/vision/ultralytics/yolov5.cc b/fastdeploy/vision/ultralytics/yolov5.cc
index 0a04eeb53..0b7e50e73 100644
--- a/fastdeploy/vision/ultralytics/yolov5.cc
+++ b/fastdeploy/vision/ultralytics/yolov5.cc
@@ -202,6 +202,11 @@ bool YOLOv5::Postprocess(
       result->scores.push_back(confidence);
     }
   }
+
+  if (result->boxes.size() == 0) {
+    return  true;
+  }
+ 
   utils::NMS(result, nms_iou_threshold);
 
   // scale the boxes to the origin image shape
diff --git a/fastdeploy/vision/utils/sort_det_res.cc b/fastdeploy/vision/utils/sort_det_res.cc
index e4a0db976..93dbb6969 100644
--- a/fastdeploy/vision/utils/sort_det_res.cc
+++ b/fastdeploy/vision/utils/sort_det_res.cc
@@ -68,7 +68,11 @@ void MergeSort(DetectionResult* result, size_t low, size_t high) {
 
 void SortDetectionResult(DetectionResult* result) {
   size_t low = 0;
-  size_t high = result->scores.size() - 1;
+  size_t high = result->scores.size();
+  if (high == 0) {
+      return;
+  }
+  high = high - 1;
   MergeSort(result, low, high);
 }