diff --git a/lib/secDetector_sdk.cpp b/lib/secDetector_sdk.cpp
index 847dd2f85f6e0caf3252d847fe0bc9a17331f496..6f47f4156a8756685e09a41f05b805096170eb22 100644
--- a/lib/secDetector_sdk.cpp
+++ b/lib/secDetector_sdk.cpp
@@ -16,15 +16,17 @@
 
 #include <string>
 #include <iostream>
+#include <list>
+#include <mutex>
 #include "../observer_agent/grpc_comm/grpc_api.h"
 
 #define ALLTOPIC 0x00FFFFFF
 using namespace std;
 static string server_address("unix:///var/run/secDetector.sock");
-static PubSubClient g_client(grpc::CreateChannel(server_address, grpc::InsecureChannelCredentials()));
 
-using Readmap = map<void *, unique_ptr<ClientReader<Message>>>;
+using Readmap = map<void *, std::pair<unique_ptr<ClientReader<Message>>, PubSubClient *>>;
 static Readmap g_reader_map;
+static mutex g_connect_mtx;
 
 #ifdef __cplusplus
 extern "C" {
@@ -32,60 +34,82 @@ extern "C" {
 
 void *secSub(const int topic)
 {
+	PubSubClient *cur_client;
 	if (topic <= 0 || topic > ALLTOPIC) {
-		printf("secSub failed, topic:%d is error\n", topic);
+		printf("lib secSub failed, topic:%d is error\n", topic);
 		return NULL;
 	}
+	g_connect_mtx.lock();
+	std::shared_ptr<Channel> channel = grpc::CreateChannel(server_address, grpc::InsecureChannelCredentials());
+	cur_client = new(PubSubClient);
+	if (cur_client == nullptr) {
+		g_connect_mtx.unlock();
+		return NULL;
+	}
+	cur_client->init(channel);
+	unique_ptr<ClientReader<Message>> reader = cur_client->Subscribe(topic);
 
-	unique_ptr<ClientReader<Message>> reader = g_client.Subscribe(topic);
-
-	if (!reader)
+	if (!reader) {
+		printf("lib secSub failed, get reader null\n");
+		delete cur_client;
+		g_connect_mtx.unlock();
 		return NULL;
+	}
 	void * ret_reader = static_cast<void *>(reader.get());
 
-	g_reader_map.insert(Readmap::value_type(ret_reader, move(reader)));
+	g_reader_map.insert(Readmap::value_type(ret_reader, std::make_pair(move(reader), cur_client)));
+	g_connect_mtx.unlock();
 	return ret_reader;
 }
 
 void secUnsub(const int topic, void *reader)
 {
+	PubSubClient *cur_client;
 	if (topic <= 0 || topic > ALLTOPIC) {
-		printf("secUnsub failed, topic:%d is error\n", topic);
+		printf("lib secUnsub failed, topic:%d is error\n", topic);
 		return;
 	}
 
 	if (!reader)
 		return;
 
-	g_client.UnSubscribe(topic);
-	
+	g_connect_mtx.lock();
 	Readmap::iterator iter = g_reader_map.find(reader);
 	if (iter != g_reader_map.end()) {
+		cur_client = iter->second.second;
+		cur_client->UnSubscribe(topic);
 		g_reader_map.erase(iter);
 		reader = NULL;
+		delete cur_client;
 	}
+	g_connect_mtx.unlock();
 }
 
 void secReadFrom(void *reader, char *data, int data_len)
 {
 	string msg("");
+	PubSubClient *cur_client;
 
 	if (!data || data_len <= 1)
 		return
 
-	memset(data, 0, data_len);
+	(void)memset(data, 0, data_len);
 
 	if (!reader)
 		return;
 
+	g_connect_mtx.lock();
 	Readmap::iterator iter = g_reader_map.find(reader);
 	if (iter != g_reader_map.end()) {
-		msg = g_client.ReadFrom(iter->second);
-		if (msg == "keepalive")
+		cur_client = iter->second.second;
+		msg = cur_client->ReadFrom(iter->second.first);
+		if (msg == "keepalive") {
+			g_connect_mtx.unlock();
 			return;
+		}
+		strncpy(data, msg.c_str(), data_len - 1);
 	}
-
-	strncpy(data, msg.c_str(), data_len - 1);
+	g_connect_mtx.unlock();
 }
 
 #ifdef __cplusplus
diff --git a/observer_agent/grpc_comm/client.cpp b/observer_agent/grpc_comm/client.cpp
index ecb54aedaf5e1d72323105bf15fbc4ff05c3c5da..d4b09480d114e36b6c29f44b451d0c87a4aacea9 100644
--- a/observer_agent/grpc_comm/client.cpp
+++ b/observer_agent/grpc_comm/client.cpp
@@ -29,6 +29,8 @@ using grpc::ClientReader;
 
 #define BUF_NUM 1024
 
+PubSubClient::PubSubClient() {}
+
 PubSubClient::PubSubClient(std::shared_ptr<Channel> channel) : stub_(SubManager::NewStub(channel))
 {
     uuid_t uuid;
@@ -38,6 +40,16 @@ PubSubClient::PubSubClient(std::shared_ptr<Channel> channel) : stub_(SubManager:
     uuid_str = std::string(uuid_temp);
 }
 
+void PubSubClient::init(std::shared_ptr<Channel> channel)
+{
+    uuid_t uuid;
+    char uuid_temp[37];
+    uuid_generate(uuid);
+    uuid_unparse(uuid, uuid_temp);
+    uuid_str = std::string(uuid_temp);
+    stub_ = SubManager::NewStub(channel);
+}
+
 std::unique_ptr<ClientReader<Message>> PubSubClient::Subscribe(const int topic)
 {
     SubscribeRequest request;
diff --git a/observer_agent/grpc_comm/grpc_api.h b/observer_agent/grpc_comm/grpc_api.h
index 44d4aa985ab466c2ab9e878ba72e0b5c022167e3..4bde109e81c849c1b2dd4193bbbec194b00a420b 100644
--- a/observer_agent/grpc_comm/grpc_api.h
+++ b/observer_agent/grpc_comm/grpc_api.h
@@ -42,7 +42,9 @@ void RunServer();
 class PubSubClient
 {
   public:
+    PubSubClient();
     PubSubClient(std::shared_ptr<Channel> channel);
+    void init(std::shared_ptr<Channel> channel);
     std::unique_ptr<ClientReader<Message>> Subscribe(const int topic);
     void Publish(const int topic, const std::string &content);
     void UnSubscribe(const int topic);