diff --git a/trinity/cli/launcher.py b/trinity/cli/launcher.py
index 3ea4f0486f..d4f171803e 100644
--- a/trinity/cli/launcher.py
+++ b/trinity/cli/launcher.py
@@ -191,7 +191,7 @@ def run(config_path: str, dlc: bool = False, plugin_dir: str = None):
         activate_data_module(
             f"{data_processor_config.data_processor_url}/experience_pipeline", config_path
         )
-    ray_namespace = f"{config.project}-{config.name}"
+    ray_namespace = config.ray_namespace
     if dlc:
         from trinity.utils.dlc_utils import setup_ray_cluster
 
diff --git a/trinity/common/config.py b/trinity/common/config.py
index f4480da311..04e90f00e9 100644
--- a/trinity/common/config.py
+++ b/trinity/common/config.py
@@ -181,6 +181,7 @@ class InferenceModelConfig:
 
     # ! DO NOT SET
     bundle_indices: str = ""
+    ray_namespace: str = ""
 
 
 @dataclass
@@ -353,6 +354,8 @@ class Config:
     checkpoint_root_dir: str = ""
     # ! DO NOT SET, automatically generated as `checkpoint_root_dir/project/name`
     checkpoint_job_dir: str = ""
+    # ! DO NOT SET, automatically generated as f"{config.project}-{config.name}"
+    ray_namespace: str = ""
 
     algorithm: AlgorithmConfig = field(default_factory=AlgorithmConfig)
     data_processor: DataProcessorConfig = field(default_factory=DataProcessorConfig)
@@ -575,6 +578,9 @@ def check_and_update(self) -> None:  # noqa: C901
         """Check and update the config."""
         self._check_deprecated()
 
+        # set namespace
+        self.ray_namespace = f"{self.project}-{self.name}"
+
         # check algorithm
         self._check_algorithm()
 
@@ -605,6 +611,9 @@ def check_and_update(self) -> None:  # noqa: C901
             self.explorer.rollout_model.max_prompt_tokens = self.model.max_prompt_tokens
         if self.explorer.rollout_model.max_response_tokens is None:
             self.explorer.rollout_model.max_response_tokens = self.model.max_response_tokens
+        self.explorer.rollout_model.ray_namespace = self.ray_namespace
+        for model in self.explorer.auxiliary_models:
+            model.ray_namespace = self.ray_namespace
 
         # check synchronizer
         self.synchronizer.explorer_world_size = (
diff --git a/trinity/common/models/vllm_async_model.py b/trinity/common/models/vllm_async_model.py
index 8a8a089afa..3b3780b360 100644
--- a/trinity/common/models/vllm_async_model.py
+++ b/trinity/common/models/vllm_async_model.py
@@ -298,6 +298,7 @@ async def init_process_group(
                 timeout,
                 update_with_checkpoint,
                 state_dict_meta,
+                self.config.ray_namespace,
             ),
         )
 
diff --git a/trinity/common/models/vllm_model.py b/trinity/common/models/vllm_model.py
index 878fe0bd9c..9ade92ab1b 100644
--- a/trinity/common/models/vllm_model.py
+++ b/trinity/common/models/vllm_model.py
@@ -112,6 +112,7 @@ def init_process_group(
                 timeout,
                 update_with_checkpoint,
                 state_dict_meta,
+                self.config.ray_namespace,
             ),
         )
 
diff --git a/trinity/common/models/vllm_worker.py b/trinity/common/models/vllm_worker.py
index 883e470381..674027b690 100644
--- a/trinity/common/models/vllm_worker.py
+++ b/trinity/common/models/vllm_worker.py
@@ -23,6 +23,7 @@ def init_process_group(
         timeout: int = 1200,
         update_with_checkpoint: bool = True,
         state_dict_meta: list = None,
+        namespace: str = "",
     ):
         """Init torch process group for model weights update"""
         assert torch.distributed.is_initialized(), "default torch process group must be initialized"
@@ -52,6 +53,7 @@ def init_process_group(
             group_name=group_name,
         )
         logger.info("vLLM init_process_group finished.")
+        self.namespace = namespace
         self._explorer_actor = None
 
     def set_state_dict_meta(self, state_dict_meta):
@@ -61,7 +63,7 @@ def update_weight(self):
         """Broadcast weight to all vllm workers from source rank 0 (actor model)"""
         assert self._state_dict_meta is not None
         if self._explorer_actor is None:
-            self._explorer_actor = ray.get_actor(name=EXPLORER_NAME)
+            self._explorer_actor = ray.get_actor(name=EXPLORER_NAME, namespace=self.namespace)
         for name, dtype_str, shape in self._state_dict_meta:
             if self._weight_update_rank == 0:
                 weight = ray.get(self._explorer_actor.get_weight.remote(name))