diff --git a/ding/model/template/q_learning.py b/ding/model/template/q_learning.py
index ece076bd81..1114fc3af0 100644
--- a/ding/model/template/q_learning.py
+++ b/ding/model/template/q_learning.py
@@ -26,16 +26,17 @@ class DQN(nn.Module):
     """
 
     def __init__(
-            self,
-            obs_shape: Union[int, SequenceType],
-            action_shape: Union[int, SequenceType],
-            encoder_hidden_size_list: SequenceType = [128, 128, 64],
-            dueling: bool = True,
-            head_hidden_size: Optional[int] = None,
-            head_layer_num: int = 1,
-            activation: Optional[nn.Module] = nn.ReLU(),
-            norm_type: Optional[str] = None,
-            dropout: Optional[float] = None
+        self,
+        obs_shape: Union[int, SequenceType],
+        action_shape: Union[int, SequenceType],
+        encoder_hidden_size_list: SequenceType = [128, 128, 64],
+        dueling: bool = True,
+        head_hidden_size: Optional[int] = None,
+        head_layer_num: int = 1,
+        activation: Optional[nn.Module] = nn.ReLU(),
+        norm_type: Optional[str] = None,
+        dropout: Optional[float] = None,
+        init_bias: Optional[float] = None,
     ) -> None:
         """
         Overview:
@@ -99,6 +100,9 @@ def __init__(
                 norm_type=norm_type,
                 dropout=dropout
             )
+            if init_bias is not None and head_cls == DuelingHead:
+                # Zero the last layer bias of advantage head
+                self.head.A[-1][0].bias.data.fill_(init_bias)
 
     def forward(self, x: torch.Tensor) -> Dict:
         """
diff --git a/ding/policy/common_utils.py b/ding/policy/common_utils.py
index 77cc9a2a17..295def03f1 100644
--- a/ding/policy/common_utils.py
+++ b/ding/policy/common_utils.py
@@ -61,12 +61,17 @@ def default_preprocess_learn(
         reward = data['reward']
         if len(reward.shape) == 1:
             reward = reward.unsqueeze(1)
-        # reward: (batch_size, nstep) -> (nstep, batch_size)
-        # reversed_shape = [i for i in range(len(reward.shape))][::-1]
-        temp_shape = [i for i in range(len(reward.shape))]
-        temp_shape = [temp_shape[-1]] + temp_shape[:-1]
-        data['reward'] = reward.permute(temp_shape).contiguous()
-        # data['reward'] = reward.transpose(0, -1).contiguous()
+        # single agent reward: (batch_size, nstep) -> (nstep, batch_size)
+        # multi-agent reward: (batch_size, agent_dim, nstep) -> (nstep, batch_size, agent_dim)
+        # Assuming 'reward' is a PyTorch tensor with shape (batch_size, nstep) or (batch_size, agent_dim, nstep)
+        if reward.ndim == 2:
+            # For a 2D tensor, simply transpose it to get (nstep, batch_size)
+            data['reward'] = reward.transpose(0, 1).contiguous()
+        elif reward.ndim == 3:
+            # For a 3D tensor, move the last dimension to the front to get (nstep, batch_size, agent_dim)
+            data['reward'] = reward.transpose(0, 2).transpose(1, 2).contiguous()
+        else:
+            raise ValueError("The 'reward' tensor must be either 2D or 3D.")
     else:
         if data['reward'].dim() == 2 and data['reward'].shape[1] == 1:
             data['reward'] = data['reward'].squeeze(-1)
diff --git a/ding/rl_utils/adder.py b/ding/rl_utils/adder.py
index 413f137827..f4faa572a8 100644
--- a/ding/rl_utils/adder.py
+++ b/ding/rl_utils/adder.py
@@ -145,10 +145,6 @@ def get_nstep_return_data(
                      for j in range(len(data) - i)] + [fake_reward for _ in range(nstep - (len(data) - i))],
                     dim=-1
                 )
-            # try:
-            #     assert len(data[i]['reward']) == 300
-            # except:
-            #     print(len(data[i]['reward']))
             data[i]['done'] = data[-1]['done']
             if correct_terminate_gamma:
                 data[i]['value_gamma'] = gamma ** (len(data) - i - 1)
diff --git a/ding/rl_utils/td.py b/ding/rl_utils/td.py
index fc85e2ce54..cb2443cf88 100644
--- a/ding/rl_utils/td.py
+++ b/ding/rl_utils/td.py
@@ -690,7 +690,10 @@ def q_nstep_td_error(
     if weight is None:
         weight = torch.ones_like(reward)
 
-    if len(action.shape) == 1 or len(action.shape) < len(q.shape):  # single agent case
+    if len(action.shape) == 1 or len(action.shape) < len(q.shape):
+        # we need to unsqueeze action and q to make them have the same shape
+        # e.g. single agent case: action is [B, ] and q is [B, ]
+        # e.g. multi agent case: action is [B, agent_num] and q is [B, agent_num, action_shape]
         action = action.unsqueeze(-1)
     elif len(action.shape) > 1:  # MARL case
         reward = reward.unsqueeze(-1)
diff --git a/dizoo/ising_env/config/ising_mfq_config.py b/dizoo/ising_env/config/ising_mfq_config.py
index 9cdf1a0dd1..1480eb379e 100644
--- a/dizoo/ising_env/config/ising_mfq_config.py
+++ b/dizoo/ising_env/config/ising_mfq_config.py
@@ -8,7 +8,7 @@
 agent_view_sight = 1
 
 ising_mfq_config = dict(
-    exp_name='ising_mfq_seed0_debug',
+    exp_name='ising_mfq_seed0',
     env=dict(
         collector_env_num=8,
         evaluator_env_num=8,
@@ -24,6 +24,7 @@
             obs_shape=obs_shape + action_shape,  # for we will concat the pre_action_prob into obs
             action_shape=action_shape,
             encoder_hidden_size_list=[128, 128, 512],
+            init_bias=0,
         ),
         nstep=3,
         discount_factor=0.99,
@@ -53,7 +54,7 @@
         type='ising_model',
         import_names=['dizoo.ising_env.envs.ising_model_env'],
     ),
-    env_manager=dict(type='base'),
+    env_manager=dict(type='subprocess'),
     policy=dict(type='dqn'),
 )
 ising_mfq_create_config = EasyDict(ising_mfq_create_config)
@@ -65,7 +66,4 @@
     from ding.model import DQN
     seed = 1
     set_pkg_seed(seed)
-    model = DQN(**ising_mfq_config.policy.model)
-    model.head.A[-1][0].bias.data.fill_(0)  # zero last layer bias
-    # print("init model successful")
-    serial_pipeline((main_config, create_config), seed=seed, model=model, max_env_step=5e4)
+    serial_pipeline((main_config, create_config), seed=seed, max_env_step=5e4)
diff --git a/dizoo/ising_env/envs/ising_model_env.py b/dizoo/ising_env/envs/ising_model_env.py
index e6659d1bb1..731d2a8c06 100644
--- a/dizoo/ising_env/envs/ising_model_env.py
+++ b/dizoo/ising_env/envs/ising_model_env.py
@@ -8,18 +8,25 @@
 from ding.envs import BaseEnv, BaseEnvTimestep
 from ding.torch_utils import to_ndarray, to_list
 from ding.utils import ENV_REGISTRY
-
-# ising_model_dir = os.path.join(os.path.dirname(__file__), 'ising_model')
-# if ising_model_dir not in sys.path:
-#     sys.path.append(ising_model_dir)
-# from ising_model.multiagent.environment import IsingMultiAgentEnv
-# import ising_model
 from dizoo.ising_env.envs.ising_model.multiagent.environment import IsingMultiAgentEnv
 import dizoo.ising_env.envs.ising_model as ising_model_
 
 
 @ENV_REGISTRY.register('ising_model')
 class IsingModelEnv(BaseEnv):
+    """
+    Overview:
+        Ising Model Environment for Multi-Agent Reinforcement Learning according to the paper: \
+        [Mean Field Multi-Agent Reinforcement Learning](https://arxiv.org/abs/1802.05438). \
+        The environment is a grid of agents, each of which can be in one of two states: \
+        spin up or spin down. The agents interact with their neighbors according to the Ising model, \
+        and the goal is to maximize the global order parameter, which is the average spin of all agents. \
+        Details of the environment can be found in the \
+        [DI-engine-Doc](https://di-engine-docs.readthedocs.io/zh-cn/latest/13_envs/index.html).
+    Interface:
+        `__init__`, `reset`, `close`, `seed`, `step`, `random_action`, `num_agents`, \
+        `observation_space`, `action_space`, `reward_space`.
+    """
 
     def __init__(self, cfg: dict) -> None:
         self._cfg = cfg