diff --git a/server/web3bcspider/services/pull_bcevent.js b/server/web3bcspider/services/pull_bcevent.js
index 3fdd6c9..954dd10 100644
--- a/server/web3bcspider/services/pull_bcevent.js
+++ b/server/web3bcspider/services/pull_bcevent.js
@@ -62,17 +62,19 @@ class PullBcEvent extends BaseService {
       return;
     }
     console.log(events);
-    for (let i in events) {
+    utils.serial
+    (events,
+     async (event) => {
       while (true) {
         try {
-          await this.saveToDb(events[i]);
-          break;
+          await this.saveToDb(event);
+          return;
         } catch (err) {
           log.error(err);
         }
         await utils.sleep(8000 + utils.randRange(500, 1500));
       }
-    }
+     });
   }
 
   async getFromBlock() {
@@ -123,7 +125,7 @@ class PullBcEvent extends BaseService {
   }
 
   async saveLastBlockNumber(blockNumber) {
-    const logHead = 'event_process.saveLastBlockNumber';
+    const logHead = this.getInstanceName() + ' event_process.saveLastBlockNumber';
     while (true) {
       const {err} = await this.conn.upsert(
         't_parameter',
@@ -148,7 +150,7 @@ class PullBcEvent extends BaseService {
   }
 
   async saveToDb(event) {
-    const logHead = 'event_process.saveToDb';
+    const logHead = this.getInstanceName() + ' event_process.saveToDb';
     while (true) {
       const nowTime = utils.getUtcTime();
       const returnValues = event['returnValues'];