diff --git a/paddle/fluid/operators/detection/generate_proposals_op.cc b/paddle/fluid/operators/detection/generate_proposals_op.cc
index a69d9c9a529f26b3981ca8d1ba226fda71b8820a..709c2dfc4b7c67d7d04074c58ce6da85b6e790fe 100644
--- a/paddle/fluid/operators/detection/generate_proposals_op.cc
+++ b/paddle/fluid/operators/detection/generate_proposals_op.cc
@@ -284,7 +284,7 @@ static inline Tensor NMS(const platform::DeviceContext &ctx, Tensor *bbox,
       selected_indices.push_back(idx);
       ++selected_num;
     }
-    sorted_indices.erase(sorted_indices.end());
+    sorted_indices.erase(sorted_indices.end() - 1);
     if (flag && eta < 1 && adaptive_threshold > 0.5) {
       adaptive_threshold *= eta;
     }