diff --git a/server/web3bcspider/services/pull_bcevent.js b/server/web3bcspider/services/pull_bcevent.js
index 5161537..8f7adef 100644
--- a/server/web3bcspider/services/pull_bcevent.js
+++ b/server/web3bcspider/services/pull_bcevent.js
@@ -26,7 +26,7 @@ class PullBcEvent extends BaseService {
   }
 
   async pullEvent() {
-    const logClass = this.getInstanceName() + ' pullEvent:';
+    const logHead = this.getInstanceName() + ' pullEvent:';
     while (true) {
       await this.bc.lockQuery();
       try {
@@ -46,7 +46,7 @@ class PullBcEvent extends BaseService {
         ++this.progInfo['pullCount'];
         return;
       } catch (err) {
-        log.error(logClass + err);
+        log.error(logHead + err);
         await utils.sleep(1000 + utils.randRange(10, 2000));
       } finally {
         await this.bc.unlockQuery();
@@ -78,7 +78,7 @@ class PullBcEvent extends BaseService {
   }
 
   async getFromBlock() {
-    const logClass = this.getInstanceName() + ' getFromBlock:';
+    const logHead = this.getInstanceName() + ' getFromBlock:';
     const firstBlockNumber  = this.getInitBlock();
     while (this.lastBlockNumber < 1) {
       try {
@@ -97,7 +97,7 @@ class PullBcEvent extends BaseService {
             this.lastBlockNumber = firstBlockNumber;
           }
         }
-        console.log(logClass, this.lastBlockNumber, this.bc.getCurrBlockNumber());
+        console.log(logHead, this.lastBlockNumber, this.bc.getCurrBlockNumber());
         while (this.lastBlockNumber + 8 > this.bc.getCurrBlockNumber()) {
           await utils.sleep(1000 + utils.randRange(500, 1500));
         }
@@ -125,7 +125,7 @@ class PullBcEvent extends BaseService {
   }
 
   async saveLastBlockNumber(blockNumber) {
-    const logClass = 'event_process.saveLastBlockNumber';
+    const logHead = 'event_process.saveLastBlockNumber';
     while (true) {
       const {err} = await this.conn.upsert(
         't_parameter',
@@ -143,14 +143,14 @@ class PullBcEvent extends BaseService {
       if (!err) {
         break;
       }
-      log.error(logClass + err);
+      log.error(logHead + err);
       await utils.sleep(5000 + utils.randRange(500, 1500));
     }
     this.lastBlockNumber = blockNumber;
   }
 
   async saveToDb(event) {
-    const logClass = 'event_process.saveToDb';
+    const logHead = 'event_process.saveToDb';
     while (true) {
       const nowTime = utils.getUtcTime();
       const returnValues = event['returnValues'];
@@ -179,7 +179,7 @@ class PullBcEvent extends BaseService {
       if (!err) {
         break;
       }
-      log.error(logClass + err);
+      log.error(logHead + err);
       await utils.sleep(5000 + utils.randRange(500, 1500));
     }
   }