diff --git a/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/SysOaProjectServiceImpl.java b/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/SysOaProjectServiceImpl.java
index ec9a3ce..93c839a 100644
--- a/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/SysOaProjectServiceImpl.java
+++ b/ruoyi-oa/src/main/java/com/ruoyi/oa/service/impl/SysOaProjectServiceImpl.java
@@ -510,8 +510,12 @@ public class SysOaProjectServiceImpl implements ISysOaProjectService {
 
         // 4. 构建更新条件，执行延期操作
         LambdaUpdateWrapper<SysOaProject> updateWrapper = new LambdaUpdateWrapper<>();
-        updateWrapper.eq(SysOaProject::getProjectId, bo.getProjectId()) // 锁定指定项目
-                .set(SysOaProject::getFinishTime, bo.getFinishTime()) // 延期日期赋值给finish_time
+        updateWrapper.eq(SysOaProject::getProjectId, bo.getProjectId()); // 锁定指定项目
+        // 关键逻辑：如果原始结束时间为空（首次延期），则将当前finish_time赋值给original_finish_time
+        if (project.getOriginalFinishTime() == null) {
+            updateWrapper.set(SysOaProject::getOriginalFinishTime, project.getFinishTime());
+        }
+        updateWrapper.set(SysOaProject::getFinishTime, bo.getFinishTime()) // 延期日期赋值给finish_time
                 .set(SysOaProject::getPostponeTime, bo.getFinishTime()) // 同步更新“延期至日期”
                 .set(SysOaProject::getIsPostpone, 1) // 标记为已延期（1=是）
                 .setSql("postpone_count = postpone_count + 1") // 延期次数+1