diff --git a/fleetrec/core/factory.py b/fleetrec/core/factory.py
index 3cfd0e5a0674ff985102aaa38d6c7840502232a1..0842a1366b3af504ddc318a1721b323fd3628bfc 100644
--- a/fleetrec/core/factory.py
+++ b/fleetrec/core/factory.py
@@ -45,7 +45,7 @@ class TrainerFactory(object):
         trainer_abs = trainers.get(train_mode, None)
 
         if trainer_abs is None:
-            if not os.path.exists(train_mode) or os.path.isfile(train_mode):
+            if not os.path.exists(train_mode) or not os.path.isfile(train_mode):
                 raise ValueError("trainer {} can not be recognized".format(train_mode))
             trainer_abs = train_mode
             train_mode = "UserDefineTrainer"
diff --git a/fleetrec/core/utils/envs.py b/fleetrec/core/utils/envs.py
index aed9e0a590456b1ab5dc67655cd2a642521f73fe..2aa6951e468887a3b23a462cdb5f0de41925f96b 100644
--- a/fleetrec/core/utils/envs.py
+++ b/fleetrec/core/utils/envs.py
@@ -21,8 +21,18 @@ global_envs = {}
 def set_runtime_envions(envs):
     assert isinstance(envs, dict)
 
+    def fatten_env_namespace(namespace_nests, local_envs):
+        for k, v in local_envs.items():
+            if isinstance(v, dict):
+                nests = copy.deepcopy(namespace_nests)
+                nests.append(k)
+                fatten_env_namespace(nests, v)
+            else:
+                global_k = ".".join(namespace_nests + [k])
+                os.environ[global_k] = str(v)
+
     for k, v in envs.items():
-        os.environ[k] = str(v)
+        fatten_env_namespace([k], v)
 
 
 def get_runtime_envion(key):
diff --git a/fleetrec/examples/runtime.yaml b/fleetrec/examples/runtime.yaml
index b639f14a28bf48605a25ea803170931459f8bdf7..70fa27c3f2cea6db19d10ffdddc2edfd7fe72983 100644
--- a/fleetrec/examples/runtime.yaml
+++ b/fleetrec/examples/runtime.yaml
@@ -3,10 +3,11 @@ trainer:
   threads: 4
 
   # for cluster training
+  strategy: "async"
   communicator:
-    strategy: "async"
     send_queue_size: 4
     min_send_grad_num_before_recv: 4
     thread_pool_size: 5
     max_merge_var_num: 4
 
+
diff --git a/fleetrec/examples/user_define/__init__.py b/fleetrec/examples/user_define/__init__.py
deleted file mode 100644
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..0000000000000000000000000000000000000000
diff --git a/fleetrec/examples/user_define/user_define_trainer.yaml b/fleetrec/examples/user_define/user_define_trainer.yaml
deleted file mode 100644
index 973bada54bea6c2c0e929d0dd7182a2003c84712..0000000000000000000000000000000000000000
--- a/fleetrec/examples/user_define/user_define_trainer.yaml
+++ /dev/null
@@ -1,2 +0,0 @@
-trainer:  "UserDefineTrainer"
-location: "/root/FleetRec/fleetrec/examples/user_define_trainer.py"
diff --git a/fleetrec/examples/user_define/user_define_trainer.py b/fleetrec/examples/user_define_trainer.py
similarity index 100%
rename from fleetrec/examples/user_define/user_define_trainer.py
rename to fleetrec/examples/user_define_trainer.py
diff --git a/fleetrec/run.py b/fleetrec/run.py
index aaae280864597c20f77ec3c08e30eb32fc677b6f..6027a678a85e12a3576e18869c334cf002598b64 100644
--- a/fleetrec/run.py
+++ b/fleetrec/run.py
@@ -21,8 +21,9 @@ def set_runtime_envs(cluster_envs, engine_yaml):
 
     if cluster_envs is None:
         cluster_envs = {}
+    cluster_envs.update(cluster_envs)
     cluster_envs.update(_envs)
-    envs.set_runtime_envions(cluster_envs)
+    # envs.set_runtime_envions(cluster_envs)
     print(envs.pretty_print_envs(cluster_envs, ("Runtime Envs", "Value")))
 
 
@@ -40,7 +41,10 @@ def get_engine(engine):
 
 def single_engine(args):
     print("use single engine to run model: {}".format(args.model))
-    single_envs = {"trainer.trainer": "SingleTrainer", "trainer.threads": "2"}
+
+    single_envs = {}
+    single_envs["trainer.trainer"] = "SingleTrainer"
+    single_envs["trainer.threads"] = "2"
     set_runtime_envs(single_envs, args.engine_extras)
     trainer = TrainerFactory.create(args.model)
     return trainer
@@ -49,7 +53,8 @@ def single_engine(args):
 def cluster_engine(args):
     print("launch cluster engine with cluster to run model: {}".format(args.model))
 
-    cluster_envs = {"trainer.trainer": "ClusterTrainer"}
+    cluster_envs = {}
+    cluster_envs["trainer.trainer"] = "ClusterTrainer"
     set_runtime_envs(cluster_envs, args.engine_extras)
 
     envs.set_runtime_envions(cluster_envs)
@@ -60,7 +65,8 @@ def cluster_engine(args):
 def cluster_mpi_engine(args):
     print("launch cluster engine with cluster to run model: {}".format(args.model))
 
-    cluster_envs = {"trainer.trainer": "CtrCodingTrainer"}
+    cluster_envs = {}
+    cluster_envs["trainer.trainer"] = "CtrCodingTrainer"
     set_runtime_envs(cluster_envs, args.engine_extras)
 
     trainer = TrainerFactory.create(args.model)
@@ -77,7 +83,9 @@ def local_cluster_engine(args):
     cluster_envs["start_port"] = 36001
     cluster_envs["log_dir"] = "logs"
     cluster_envs["trainer.trainer"] = "ClusterTrainer"
-    cluster_envs["trainer.strategy.mode"] = "async"
+    cluster_envs["trainer.strategy"] = "async"
+    cluster_envs["trainer.threads"] = "2"
+    cluster_envs["CPU_NUM"] = "2"
 
     set_runtime_envs(cluster_envs, args.engine_extras)