diff --git a/yuthon_hr_attendance/models/overtime_approval.py b/yuthon_hr_attendance/models/overtime_approval.py
index ea0b55193..9fbf654f9 100644
--- a/yuthon_hr_attendance/models/overtime_approval.py
+++ b/yuthon_hr_attendance/models/overtime_approval.py
@@ -70,7 +70,9 @@ class OvertimeApprovals(models.Model):
         for rec in self:
             if not rec.employee_ids or not rec.start_time:
                 continue
-            current_date = (rec.start_time + timedelta(hours=8)).date()
+            # 当前记录的时间段（数据库存 UTC，统一比较无需 +8）
+            cur_start = rec.start_time
+            cur_end = rec.end_time
             for employee in rec.employee_ids:
                 if not employee.user_id:
                     continue
@@ -87,12 +89,28 @@ class OvertimeApprovals(models.Model):
                     target_record = target_model.browse(wf_rec.res_id)
                     if not target_record.exists() or not target_record.start_time:
                         continue
-                    exist_date = (target_record.start_time + timedelta(hours=8)).date()
-                    if exist_date == current_date:
-                        raise UserError('员工【%s】在【%s】已有加班记录，不可重复提交！' % (
-                            employee.name,
-                            current_date
-                        ))
+                    exist_start = target_record.start_time
+                    exist_end = target_record.end_time
+                    # 新旧记录都有结束时间：按时间区间是否有交集判断
+                    # （允许同一天不重叠的早/晚加班，如 08:00-12:00 与 18:00-22:00）
+                    if cur_end and exist_end:
+                        # 两个闭区间 [a,b] 与 [c,d] 有交集的充要条件：max(a,c) < min(b,d)
+                        if max(cur_start, exist_start) < min(cur_end, exist_end):
+                            raise UserError(
+                                '员工【%s】在【%s】的加班时间段与已有记录冲突，不可重复提交！' % (
+                                    employee.name,
+                                    (cur_start + timedelta(hours=8)).strftime('%Y-%m-%d %H:%M'),
+                                )
+                            )
+                    else:
+                        # 缺少结束时间无法判断交集时，退化为按日期判断，避免漏拦
+                        exist_date = (exist_start + timedelta(hours=8)).date()
+                        current_date = (cur_start + timedelta(hours=8)).date()
+                        if exist_date == current_date:
+                            raise UserError('员工【%s】在【%s】已有加班记录，不可重复提交！' % (
+                                employee.name,
+                                current_date
+                            ))
             for employee in rec.employee_ids:
                 holiday_status_id = self.env['hr.leave.type'].search([('name', '=', '补休')])
                 start_year = rec.start_time.date().year