diff --git a/ppdet/modeling/post_process.py b/ppdet/modeling/post_process.py
index 099765e33b2ee5ed1bb0f3371a889eeaa02c0866..765e05fbf732a4d17d9b441ed355b4803ca64ab0 100644
--- a/ppdet/modeling/post_process.py
+++ b/ppdet/modeling/post_process.py
@@ -100,7 +100,6 @@ class BBoxPostProcess(nn.Layer):
             if bbox_num[i] == 0:
                 bboxes_i = fake_bboxes
                 bbox_num_i = fake_bbox_num
-                id_start += 1
             else:
                 bboxes_i = bboxes[id_start:id_start + bbox_num[i], :]
                 bbox_num_i = bbox_num[i]