diff --git a/workflow-engine-core/src/main/resources/sql/upgrade_to_1.4.2.sql b/workflow-engine-core/src/main/resources/sql/upgrade_to_1.4.2.sql
index 68126ece0..773b7040c 100644
--- a/workflow-engine-core/src/main/resources/sql/upgrade_to_1.4.2.sql
+++ b/workflow-engine-core/src/main/resources/sql/upgrade_to_1.4.2.sql
@@ -26,3 +26,8 @@ create table `workflow-engine`.ext_ax_process_log
     update_at           datetime      default CURRENT_TIMESTAMP not null on update CURRENT_TIMESTAMP comment '更新时间',
     is_delete           bigint        default 0                 not null comment '是否删除'
 ) comment '审批日志持久化';
+
+create unique index idx_process_task_status
+    on ext_ax_process_log (process_instance_id, task_id, status, is_delete);
+
+