diff --git a/paddle/fluid/distributed/fleet_executor/CMakeLists.txt b/paddle/fluid/distributed/fleet_executor/CMakeLists.txt
index ff8ed811ee6f84..e2c79874c74d32 100755
--- a/paddle/fluid/distributed/fleet_executor/CMakeLists.txt
+++ b/paddle/fluid/distributed/fleet_executor/CMakeLists.txt
@@ -50,6 +50,7 @@ cc_library(
        collective_helper
        op_registry
        executor_gc_helper
+	   flags
        gflags
        glog
        ${BRPC_DEPS})
diff --git a/paddle/fluid/distributed/fleet_executor/carrier.cc b/paddle/fluid/distributed/fleet_executor/carrier.cc
index 9b023e12a8893c..411fe8872e44c1 100644
--- a/paddle/fluid/distributed/fleet_executor/carrier.cc
+++ b/paddle/fluid/distributed/fleet_executor/carrier.cc
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "paddle/fluid/distributed/fleet_executor/carrier.h"
+#include "gflags/gflags.h"
 
 #include <algorithm>
 #include <vector>
@@ -28,6 +29,8 @@
 #include "paddle/fluid/framework/variable.h"
 #include "paddle/fluid/framework/variable_helper.h"
 
+DECLARE_bool(fleetexecutor_debug_mode);
+
 namespace paddle {
 namespace distributed {
 
@@ -38,6 +41,7 @@ USE_INTERCEPTOR(Sink);
 USE_INTERCEPTOR(Cond);
 USE_INTERCEPTOR(Start);
 
+
 void Carrier::Init(
     int64_t rank,
     const std::unordered_map<int64_t, int64_t>& interceptor_id_to_rank) {
@@ -48,6 +52,69 @@ void Carrier::Init(
   thread_num_ = 1;
   thread_pool_.SetThreadNum(thread_num_);
   thread_pool_.Start();
+
+  test_thread_ = std::thread([this]() { loop_to_send_msg(); });
+  cache_begin_ == std::chrono::steady_clock::now();
+}
+
+void Carrier::loop_to_send_msg() {
+  //VLOG(3) << "loop_send_msg loop now";
+  while(1){
+	  while(1){
+		int  q_size=0;
+		std::chrono::time_point<std::chrono::steady_clock> c_begin;
+		{
+		  std::lock_guard<std::mutex> lock(running_mutex_);
+		  q_size = messages_for_test_.size();
+		  c_begin = cache_begin_;
+		}
+
+		auto now = std::chrono::steady_clock::now();
+		auto delta = std::chrono::duration_cast<std::chrono::milliseconds>(now - c_begin).count();
+		
+		if(q_size<2 && delta <5000){
+		  //std::time_t now_c = std::chrono::system_clock::to_time_t(now);
+		  //VLOG(3) << "messages_for_test_ q_size:" << q_size 
+		  //	    << ", delta:" << delta << ", will sleep 1000ms" ;//<<", now:" << now_c;
+		  std::this_thread::sleep_for(std::chrono::milliseconds(10));
+		  continue;
+		}else{
+		  VLOG(3) << "messages_for_test_ q_size:" << q_size 
+			  << ", delta:" << delta << ", will send all msg" ;
+		  break;
+		}
+	  }
+
+	 {
+	  std::lock_guard<std::mutex> lock(running_mutex_);
+	  while (!messages_for_test_.empty()) {
+		  auto msg=messages_for_test_.back();
+		  messages_for_test_.pop_back();
+
+		  int64_t src_id = msg.src_id();
+		  // TODO(liyurui): compatible solution, will be removed completely in the
+		  // future
+		  if (interceptor_id_to_rank_.find(src_id) == interceptor_id_to_rank_.end() &&
+			  src_id == SOURCE_ID) {
+			src_id = msg.dst_id();
+		  }
+		  int64_t dst_id = msg.dst_id();
+		  int64_t dst_rank = GetRank(dst_id);
+
+		  VLOG(3) << "Send a cached message from interceptor " << src_id
+			<< " to interceptor " << dst_id
+			<< ", which are in different ranks, scope_idx:" << msg.scope_idx();
+
+		  if(!GlobalVal<MessageBus>::Get()->Send(dst_rank, msg)){
+			  LOG(FATAL) << "send msg error";
+		  }
+		  std::this_thread::sleep_for(std::chrono::milliseconds(2));
+	  }
+
+    cache_begin_ = std::chrono::steady_clock::now();
+   }
+  }
+  VLOG(3) << "reset cache_begin_";
 }
 
 void Carrier::Init(
@@ -95,6 +162,9 @@ void Carrier::Init(
   thread_pool_.SetThreadNum(thread_num_);
   thread_pool_.Start();
 
+  test_thread_ = std::thread([this]() { loop_to_send_msg(); });
+  cache_begin_ == std::chrono::steady_clock::now();
+
   CreateInterceptors();
   is_init_ = true;
 }
@@ -230,12 +300,39 @@ bool Carrier::Send(const InterceptorMessage& msg) {
     VLOG(3) << "Send a message from interceptor " << src_id
             << " to interceptor " << dst_id << ", which are in the same ranks.";
     return EnqueueInterceptorMessage(msg);
-  } else {
+  } 
+
+  if(!FLAGS_fleetexecutor_debug_mode){
+	 VLOG(3) << "Send a message from interceptor " << src_id
+			  << " to interceptor " << dst_id
+			  << ", which are in different ranks.";
+	return GlobalVal<MessageBus>::Get()->Send(dst_rank, msg);
+  }
+
+  if(msg.message_type() != DATA_IS_READY){
     VLOG(3) << "Send a message from interceptor " << src_id
-            << " to interceptor " << dst_id
-            << ", which are in different ranks.";
+          << " to interceptor " << dst_id
+          << ", which are in different ranks.";
     return GlobalVal<MessageBus>::Get()->Send(dst_rank, msg);
   }
+  
+  {
+    VLOG(3) << "prepare executor debug";
+
+    std::unique_lock<std::mutex> lock(running_mutex_);
+    if(messages_for_test_.empty()){
+      cache_begin_ = std::chrono::steady_clock::now();
+      //std::time_t now_c = std::chrono::system_clock::to_time_t(cache_begin_));
+      VLOG(3) << "messages_for_test_ empty, reset cache_begin_";
+    }
+
+    VLOG(3) << "Cache message from interceptor " << src_id
+		<< " to interceptor " << dst_id
+		<< ", which are in different ranks, scope_idx:" << msg.scope_idx();
+    messages_for_test_.emplace_back(msg);
+  }
+
+  return true;
 }
 
 Interceptor* Carrier::SetInterceptor(int64_t interceptor_id,
diff --git a/paddle/fluid/distributed/fleet_executor/carrier.h b/paddle/fluid/distributed/fleet_executor/carrier.h
index 8e7fad3e892d87..9591c2adcb0b1d 100644
--- a/paddle/fluid/distributed/fleet_executor/carrier.h
+++ b/paddle/fluid/distributed/fleet_executor/carrier.h
@@ -21,6 +21,12 @@
 #include <string>
 #include <unordered_map>
 #include <vector>
+#include <queue>
+#include <thread>
+
+#include <chrono>
+
+
 
 #include "paddle/fluid/distributed/fleet_executor/interceptor.h"
 #include "paddle/fluid/distributed/fleet_executor/interceptor_message.pb.h"
@@ -118,6 +124,12 @@ class Carrier final {
   int thread_num_;
   TaskLoopThreadPool thread_pool_;
   std::unordered_set<int64_t> interceptor_ids_;
+
+  std::deque<InterceptorMessage> messages_for_test_;
+  std::thread test_thread_;
+  std::chrono::time_point<std::chrono::steady_clock> cache_begin_;
+
+  void loop_to_send_msg();
 };
 
 }  // namespace distributed
diff --git a/paddle/fluid/platform/flags.cc b/paddle/fluid/platform/flags.cc
index 518aabbb09ead8..cfd09f34bc9b6b 100644
--- a/paddle/fluid/platform/flags.cc
+++ b/paddle/fluid/platform/flags.cc
@@ -1020,3 +1020,17 @@ PADDLE_DEFINE_EXPORTED_bool(
 PADDLE_DEFINE_EXPORTED_string(jit_engine_type,
                               "Predictor",
                               "Choose default funciton type in JitLayer.");
+
+/**
+ * Executor debug FLAG
+ * Name: FLAGS_fleetexecutor_debug_mode
+ * Since Version: 2.5
+ * Value Range: bool
+ * default=False
+ * Example:
+ * Note:
+ * FLAGS_fleetexecutor_debug_mode == 1, enter in debug mode 
+ */
+PADDLE_DEFINE_EXPORTED_bool(fleetexecutor_debug_mode,
+                              false,
+                              "Enter in FleetExecutor debug mode.");
\ No newline at end of file