diff --git a/src/main/resources/mapper/qms/QcMapper.xml b/src/main/resources/mapper/qms/QcMapper.xml
index 5d45af2..20ac71b 100644
--- a/src/main/resources/mapper/qms/QcMapper.xml
+++ b/src/main/resources/mapper/qms/QcMapper.xml
@@ -2953,6 +2953,8 @@
             a.site,
             a.bu_no,
             a.inspection_no,
+            -- 明细唯一顺序号：用于前端回传后精确更新对应明细行，避免同 item_no 多行被互相覆盖
+            a.order_id,
             a.template_id,
             a.sampling_level_no,
             a.sampling_level_desc,
@@ -3046,7 +3048,20 @@
             sampling_qty = #{samplingQty,jdbcType=DECIMAL},
             text_value = #{textValue},
             number_value = #{numberValue,jdbcType=DECIMAL}
-        WHERE inspection_no = #{inspectionNo} and item_no = #{itemNo} and site = #{site} and bu_no = #{buNo}
+        WHERE inspection_no = #{inspectionNo}
+          and site = #{site}
+          and bu_no = #{buNo}
+        <choose>
+            <!-- 优先使用 order_id 精确定位单行，避免同 item_no 多行时被批量覆盖 -->
+            <when test="orderId != null">
+                and order_id = #{orderId,jdbcType=INTEGER}
+            </when>
+            <!-- 兼容历史数据：若 order_id 为空，退回 item_no + object_id 组合定位 -->
+            <otherwise>
+                and item_no = #{itemNo}
+                and object_id = #{objectId}
+            </otherwise>
+        </choose>
     </update>
 
     <!-- 查询该记录明细是否已存在 -->