diff --git a/apps/em/migrations/0022_alter_equipment_check_days_number.py b/apps/em/migrations/0022_alter_equipment_check_days_number.py
deleted file mode 100644
index 7b10553e..00000000
--- a/apps/em/migrations/0022_alter_equipment_check_days_number.py
+++ /dev/null
@@ -1,18 +0,0 @@
-# Generated by Django 3.2.12 on 2024-12-03 09:35
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('em', '0021_auto_20241203_1531'),
-    ]
-
-    operations = [
-        migrations.AlterField(
-            model_name='equipment',
-            name='check_days_number',
-            field=models.PositiveSmallIntegerField(default=7, verbose_name='临期检验预警(天)'),
-        ),
-    ]
diff --git a/apps/em/models.py b/apps/em/models.py
index 6d56c186..ff7d6877 100644
--- a/apps/em/models.py
+++ b/apps/em/models.py
@@ -110,7 +110,7 @@ class Equipment(CommonBModel):
     check_date = models.DateField("最近校准检查日期", blank=True, null=True)
     next_check_date = models.DateField("预计下次校准检查日期", blank=True, null=True)
     state_measure = models.PositiveIntegerField("计量设备状态", choices=measure_state_choices, default=EQ_WAIT)
-    check_days_number = models.PositiveSmallIntegerField("临期检验预警(天)", default=7)
+    check_days_number = models.PositiveSmallIntegerField("临期检验预警(天)", null=True, blank=True)
     power_kw = models.FloatField("功率", null=True, blank=True)
 
     coordinates = models.JSONField("坐标", default=dict, blank=True)