diff --git a/apps/qm/migrations/0048_auto_20250318_1342.py b/apps/qm/migrations/0048_auto_20250318_1342.py
new file mode 100644
index 00000000..65c57231
--- /dev/null
+++ b/apps/qm/migrations/0048_auto_20250318_1342.py
@@ -0,0 +1,28 @@
+# Generated by Django 3.2.12 on 2025-03-18 05:42
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('qm', '0047_ftestwork_count_ok_full'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='qct',
+            name='max_defect_rate',
+            field=models.FloatField(blank=True, default=0.5, null=True, verbose_name='最大不合格率'),
+        ),
+        migrations.AddField(
+            model_name='qctdefect',
+            name='is_default',
+            field=models.BooleanField(default=False, verbose_name='是否默认缺陷'),
+        ),
+        migrations.AddField(
+            model_name='qctmat',
+            name='max_defect_rate',
+            field=models.FloatField(blank=True, default=0.5, null=True, verbose_name='最大不合格率'),
+        ),
+    ]
diff --git a/apps/qm/models.py b/apps/qm/models.py
index 49c29682..f832e4e9 100644
--- a/apps/qm/models.py
+++ b/apps/qm/models.py
@@ -155,6 +155,7 @@ class Qct(CommonAModel):
     testitems = models.ManyToManyField(TestItem, verbose_name="检测项", blank=True, through='qm.qcttestitem')
     defects = models.ManyToManyField(Defect, verbose_name="缺陷项", blank=True, through='qm.qctdefect')
     materials = models.ManyToManyField(Material, verbose_name="物料", blank=True, through='qm.qctmat')
+    max_defect_rate = models.FloatField('最大不合格率', default=0.5, null=True, blank=True)
 
     @property
     def qct_testitems(self):
@@ -183,6 +184,14 @@ class Qct(CommonAModel):
             raise ParseError("存在多个质检表，请手动选择")
         return qct
     
+    @property
+    def defect_default(self):
+        qctdefect = QctDefect.objects.filter(qct=self, is_default=True)
+        if qctdefect.exists():
+            return qctdefect.first().defect
+        else:
+            return None
+    
     @classmethod
     def get_qs(cls, materialId:str, tag:str):
         qct_qs = Qct.objects.filter(qctmat__material__id=materialId, tags__contains=tag)
@@ -199,6 +208,7 @@ class QctTestItem(BaseModel):
 
 class QctDefect(BaseModel):
     qct = models.ForeignKey(Qct, verbose_name="质检模板", on_delete=models.CASCADE, related_name="qctdefect")
+    is_default = models.BooleanField('是否默认缺陷', default=False)
     defect = models.ForeignKey(Defect, verbose_name="缺陷项", on_delete=models.CASCADE)
     rule_expression = models.TextField('判定表达式', null=True, blank=True)
     note = models.TextField('备注', null=True, blank=True)
@@ -209,6 +219,7 @@ class QctMat(BaseModel):
     material = models.ForeignKey(Material, verbose_name="物料", on_delete=models.CASCADE)
     tracing = models.CharField('追溯层级', default=QC_T, choices=QC_TRACE_CHOICES,
                                max_length=20, help_text=str(QC_TRACE_CHOICES))
+    max_defect_rate = models.FloatField('最大不合格率', default=0.5, null=True, blank=True)
     
 
 class QuaStat(CommonBDModel):
diff --git a/apps/qm/views.py b/apps/qm/views.py
index a60ff3fb..702667e7 100644
--- a/apps/qm/views.py
+++ b/apps/qm/views.py
@@ -78,6 +78,17 @@ class QctDefectViewSet(CustomModelViewSet):
     filterset_fields = ["qct", "defect"]
     ordering = ["qct", "sort"]
 
+    @transaction.atomic
+    def perform_create(self, serializer):
+        ins: QctDefect = serializer.save()
+        if ins.is_default:
+            QctDefect.objects.filter(qct=ins.qct).exclude(id=ins.id).update(is_default=False)
+    
+    def perform_update(self, serializer):
+        ins: QctDefect = serializer.save()
+        if ins.is_default:
+            QctDefect.objects.filter(qct=ins.qct).exclude(id=ins.id).update(is_default=False)
+
 class QctMatViewSet(CustomModelViewSet):
     """检测物料