diff --git a/doc/XXL-JOB官方文档.md b/doc/XXL-JOB官方文档.md
index 12b98239..52eec775 100644
--- a/doc/XXL-JOB官方文档.md
+++ b/doc/XXL-JOB官方文档.md
@@ -1517,7 +1517,7 @@ Tips: 历史版本(V1.3.x)目前已经Release至稳定版本, 进入维护阶段
 - 6、登录界面取消默认填写的登录账号密码；
 - 7、[ING]cron在线生成工具；
 - 8、[ING]任务、执行器数据全量本地缓存；新增消息表广播通知；
-- 9、任务触发组件优化，常规1s预加载一次，预加载轮空时主动休眠4s，降低加载频率以及对DB压力；
+- 9、任务触发组件优化，预加载频率正常1s一次，当预加载轮空时主动休眠一个加载周期，动态降低加载频率从而降低DB压力；
 - 10、注册监控线程优化，降低死锁几率；
 - 11、调度组件优化：针对永远不会触发的Cron禁止配置和启动；任务Cron最后一次触发后再也不会触发时，比如一次性任务，主动停止相关任务；
 - 12、任务列表交互优化，支持查看任务所属执行器的注册节点；
diff --git a/xxl-job-admin/src/main/java/com/xxl/job/admin/core/thread/JobScheduleHelper.java b/xxl-job-admin/src/main/java/com/xxl/job/admin/core/thread/JobScheduleHelper.java
index bc1e82ba..d3c51b82 100644
--- a/xxl-job-admin/src/main/java/com/xxl/job/admin/core/thread/JobScheduleHelper.java
+++ b/xxl-job-admin/src/main/java/com/xxl/job/admin/core/thread/JobScheduleHelper.java
@@ -194,9 +194,8 @@ public class JobScheduleHelper {
                     // Wait seconds, align second
                     if (cost < 1000) {  // scan-overtime, not wait
                         try {
-                            // pre-read success, exist job in pre-read period, wait 1s;
-                            // pre-read fail, no exist job in pre-read period, wait 4s
-                            TimeUnit.MILLISECONDS.sleep((preReadSuc?1000:4000) - System.currentTimeMillis()%1000);
+                            // pre-read period: success > scan each second; fail > skip this period;
+                            TimeUnit.MILLISECONDS.sleep((preReadSuc?1000:PRE_READ_MS) - System.currentTimeMillis()%1000);
                         } catch (InterruptedException e) {
                             if (!scheduleThreadToStop) {
                                 logger.error(e.getMessage(), e);
diff --git a/xxl-job-admin/src/main/resources/mybatis-mapper/XxlJobInfoMapper.xml b/xxl-job-admin/src/main/resources/mybatis-mapper/XxlJobInfoMapper.xml
index 46286fc5..0407011a 100644
--- a/xxl-job-admin/src/main/resources/mybatis-mapper/XxlJobInfoMapper.xml
+++ b/xxl-job-admin/src/main/resources/mybatis-mapper/XxlJobInfoMapper.xml
@@ -212,7 +212,7 @@
 		SELECT <include refid="Base_Column_List" />
 		FROM xxl_job_info AS t
 		WHERE t.trigger_status = 1
-			and t.trigger_next_time<![CDATA[ < ]]> #{maxNextTime}
+			and t.trigger_next_time<![CDATA[ <= ]]> #{maxNextTime}
 	</select>
 
 	<update id="scheduleUpdate" parameterType="com.xxl.job.admin.core.model.XxlJobInfo"  >