diff --git a/deepmd/pt/train/training.py b/deepmd/pt/train/training.py
index a7b9e25b4..c3d603dad 100644
--- a/deepmd/pt/train/training.py
+++ b/deepmd/pt/train/training.py
@@ -1030,10 +1030,13 @@ def save_model(self, save_path, lr=0.0, step=0):
             if dist.is_available() and dist.is_initialized()
             else self.wrapper
         )
-        module.train_infos["lr"] = lr
+        module.train_infos["lr"] = float(lr)
         module.train_infos["step"] = step
+        optim_state_dict = deepcopy(self.optimizer.state_dict())
+        for item in optim_state_dict["param_groups"]:
+            item["lr"] = float(item["lr"])
         torch.save(
-            {"model": module.state_dict(), "optimizer": self.optimizer.state_dict()},
+            {"model": module.state_dict(), "optimizer": optim_state_dict},
             save_path,
         )
         checkpoint_dir = save_path.parent
diff --git a/source/tests/pt/test_change_bias.py b/source/tests/pt/test_change_bias.py
index f76be40b3..febc439f5 100644
--- a/source/tests/pt/test_change_bias.py
+++ b/source/tests/pt/test_change_bias.py
@@ -92,7 +92,9 @@ def test_change_bias_with_data(self):
         run_dp(
             f"dp --pt change-bias {self.model_path!s} -s {self.data_file[0]} -o {self.model_path_data_bias!s}"
         )
-        state_dict = torch.load(str(self.model_path_data_bias), map_location=DEVICE)
+        state_dict = torch.load(
+            str(self.model_path_data_bias), map_location=DEVICE, weights_only=True
+        )
         model_params = state_dict["model"]["_extra_state"]["model_params"]
         model_for_wrapper = get_model_for_wrapper(model_params)
         wrapper = ModelWrapper(model_for_wrapper)
@@ -114,7 +116,7 @@ def test_change_bias_with_data_sys_file(self):
             f"dp --pt change-bias {self.model_path!s} -f {tmp_file.name} -o {self.model_path_data_file_bias!s}"
         )
         state_dict = torch.load(
-            str(self.model_path_data_file_bias), map_location=DEVICE
+            str(self.model_path_data_file_bias), map_location=DEVICE, weights_only=True
         )
         model_params = state_dict["model"]["_extra_state"]["model_params"]
         model_for_wrapper = get_model_for_wrapper(model_params)
@@ -134,7 +136,9 @@ def test_change_bias_with_user_defined(self):
         run_dp(
             f"dp --pt change-bias {self.model_path!s} -b {' '.join([str(_) for _ in user_bias])} -o {self.model_path_user_bias!s}"
         )
-        state_dict = torch.load(str(self.model_path_user_bias), map_location=DEVICE)
+        state_dict = torch.load(
+            str(self.model_path_user_bias), map_location=DEVICE, weights_only=True
+        )
         model_params = state_dict["model"]["_extra_state"]["model_params"]
         model_for_wrapper = get_model_for_wrapper(model_params)
         wrapper = ModelWrapper(model_for_wrapper)