diff --git a/yuthon_hr_attendance/models/overtime_approval.py b/yuthon_hr_attendance/models/overtime_approval.py
index 179b35065..4c2611136 100644
--- a/yuthon_hr_attendance/models/overtime_approval.py
+++ b/yuthon_hr_attendance/models/overtime_approval.py
@@ -58,6 +58,23 @@ class OvertimeApprovals(models.Model):
     name_title = fields.Char(default=_get_default_name_title)
     self_users_ids = fields.Many2many('res.users', string="当前经办人", default=lambda self: [(6, 0, [self.env.user.id])])
 
+    @api.constrains('start_time')
+    def _check_start_time(self):
+        for rec in self:
+            workflow_records = self.env['soong.workflow.record'].search([
+                ('workflow_id.name', '=', '加班'),
+                ('create_uid', '=', self.env.user.id),
+            ])
+            if not workflow_records:
+                continue
+            for wf_rec in workflow_records:
+                target_model = self.env[wf_rec.res_model]
+                target_record = target_model.browse(wf_rec.res_id)
+                if not target_record.exists() or not target_record.start_time:
+                    continue
+                if target_record.start_time.date() == rec.start_time.date():
+                    raise UserError('当天已有加班审批，请重新选择开始时间')
+
     def open_record(self):
         if self.start_time and self.end_time and self.employee_ids:
             start_date = fields.Date.to_date(self.start_time)