diff --git a/tools/infer_det.py b/tools/infer_det.py
index bb2cca7362e81494018aa3471664d60bef1b852c..1c679e0faf0d3ebdb6ca7ed4c317ce3eecfa910f 100755
--- a/tools/infer_det.py
+++ b/tools/infer_det.py
@@ -53,6 +53,7 @@ def draw_det_res(dt_boxes, config, img, img_name, save_path):
         logger.info("The detected Image saved in {}".format(save_path))
 
 
+@paddle.no_grad()
 def main():
     global_config = config['Global']