diff --git a/backend/app/crud/qc_work_order.py b/backend/app/crud/qc_work_order.py
index 884954d7..5b17b3a2 100644
--- a/backend/app/crud/qc_work_order.py
+++ b/backend/app/crud/qc_work_order.py
@@ -23,6 +23,7 @@ from app.crud.qc_inbound_lab_storage_sort import (
 from app.crud.collection_protocol import urls_to_attachment_list
 from app.utils.sample_special import apply_special_to_item_from_samples
 from app.crud import sample_reception as sample_reception_svc
+from app.crud.temp_qc_target import resolve_temp_qc_target
 from app.crud.sample_reception import _donation_sample_id_col
 from app.crud import sample_reception_check_result as check_result_svc
 from app.crud.cell_product import _enrich_product_dicts as _cp_enrich, _row_to_dict as _cp_row_to_dict, get_cell_product
diff --git a/backend/app/crud/temp_qc_target.py b/backend/app/crud/temp_qc_target.py
new file mode 100644
index 00000000..74b9db82
--- /dev/null
+++ b/backend/app/crud/temp_qc_target.py
@@ -0,0 +1,22 @@
+"""临时质检对象：系统产品 / 外部编号互斥归一化。"""
+
+from typing import Optional, Tuple
+
+
+def resolve_temp_qc_target(
+    *,
+    cell_product_id: Optional[str] = None,
+    external_target_code: Optional[str] = None,
+) -> Tuple[Optional[str], Optional[str]]:
+    """临时质检对象互斥归一化。返回 (cell_product_id|None, external_target_code|None)。"""
+    cp = (cell_product_id or "").strip() or None
+    ext = (external_target_code or "").strip() or None
+    if cp and ext:
+        raise ValueError("质检对象不能同时选择系统产品并填写外部编号")
+    if not cp and not ext:
+        raise ValueError("请选择质检对象或填写外部编号")
+    if ext and len(ext) > 64:
+        raise ValueError("外部编号最长 64 个字符")
+    if ext:
+        return None, ext
+    return cp, None
diff --git a/backend/app/models/models.py b/backend/app/models/models.py
index 4523b93a..c7480bae 100644
--- a/backend/app/models/models.py
+++ b/backend/app/models/models.py
@@ -1685,6 +1685,7 @@ class BizQcWorkOrder(Base):
     infusion_schedule_id = Column(String(64), nullable=True, comment="中试输注计划ID（出库质检关联）")
     biz_type = Column(String(20), nullable=True, comment="业务类型: pilot_service=中试服务, clinical_application=临床应用")
     cell_product_id = Column(String(64), nullable=True, comment="质检对象-细胞产品ID")
+    external_target_code = Column(String(64), nullable=True, comment="外部质检对象编号（手写）")
     production_work_order_id = Column(String(64), nullable=True, comment="关联生产工单ID（生产过程触发时）")
     production_task_id = Column(String(64), nullable=True, comment="关联生产任务ID（可选）")
     production_step_output_id = Column(String(64), nullable=True, comment="关联生产任务步骤产出物ID（生产过程触发时）")
diff --git a/backend/tests/test_temp_qc_target_resolve.py b/backend/tests/test_temp_qc_target_resolve.py
new file mode 100644
index 00000000..029ab794
--- /dev/null
+++ b/backend/tests/test_temp_qc_target_resolve.py
@@ -0,0 +1,44 @@
+"""临时质检对象：系统产品 / 外部编号互斥归一化。"""
+
+import unittest
+
+from app.crud.temp_qc_target import resolve_temp_qc_target
+
+
+class TestResolveTempQcTarget(unittest.TestCase):
+    def test_cell_product_only(self):
+        cp, ext = resolve_temp_qc_target(
+            cell_product_id="  pid-1  ", external_target_code="  "
+        )
+        self.assertEqual(cp, "pid-1")
+        self.assertIsNone(ext)
+
+    def test_external_only(self):
+        cp, ext = resolve_temp_qc_target(
+            cell_product_id="", external_target_code="  EXT-1  "
+        )
+        self.assertIsNone(cp)
+        self.assertEqual(ext, "EXT-1")
+
+    def test_both_raises(self):
+        with self.assertRaises(ValueError) as ctx:
+            resolve_temp_qc_target(
+                cell_product_id="pid", external_target_code="EXT"
+            )
+        self.assertIn("不能同时", str(ctx.exception))
+
+    def test_neither_raises(self):
+        with self.assertRaises(ValueError) as ctx:
+            resolve_temp_qc_target(cell_product_id="", external_target_code="")
+        self.assertIn("质检对象", str(ctx.exception))
+
+    def test_external_too_long(self):
+        with self.assertRaises(ValueError) as ctx:
+            resolve_temp_qc_target(
+                cell_product_id="", external_target_code="x" * 65
+            )
+        self.assertIn("64", str(ctx.exception))
+
+
+if __name__ == "__main__":
+    unittest.main()