diff --git a/pdseg/train.py b/pdseg/train.py
index 67a7bf5a991c45e1e007a613ee6d0b6e8df7c280..7b155a2b44e0dad56cd818150e75d8de5fb81ee9 100644
--- a/pdseg/train.py
+++ b/pdseg/train.py
@@ -353,6 +353,9 @@ def train(cfg):
     else:
         print_info("Use multi-thread reader")
 
+    # 存储评估时最高mIoU
+    best_mIoU = 0
+
     for epoch in range(begin_epoch, cfg.SOLVER.NUM_EPOCHS + 1):
         py_reader.start()
         while True:
@@ -445,6 +448,14 @@ def train(cfg):
                     log_writer.add_scalar('Evaluate/mean_acc', mean_acc,
                                           global_step)
 
+                # 将最优模型拷贝一份至best_model中
+                if mean_iou > best_mIoU:
+                    best_mIoU = mean_iou
+                    best_model_dir = os.path.join(cfg.TRAIN.MODEL_SAVE_DIR, 'best_model')
+                    if os.path.exists(best_model_dir):
+                        shutil.rmtree(best_model_dir)
+                    shutil.copytree(ckpt_dir, best_model_dir)
+
             # Use Tensorboard to visualize results
             if args.use_tb and cfg.DATASET.VIS_FILE_LIST is not None:
                 visualize(