diff --git a/src/main/java/com/xujie/sys/modules/erf/data/ErfExpApplyData.java b/src/main/java/com/xujie/sys/modules/erf/data/ErfExpApplyData.java
index 98087d99..a4b5e272 100644
--- a/src/main/java/com/xujie/sys/modules/erf/data/ErfExpApplyData.java
+++ b/src/main/java/com/xujie/sys/modules/erf/data/ErfExpApplyData.java
@@ -20,10 +20,15 @@ public class ErfExpApplyData implements Serializable {
     private static final long serialVersionUID = 1L;
 
     /**
-     * 申请单号
+     * 申请单号（试验单号）
      */
     private String applyNo;
 
+    /**
+     * 原始申请单号（编辑时传入，用于定位原记录；为空表示新增）
+     */
+    private String originalApplyNo;
+
     /**
      * 事业部代码
      */
diff --git a/src/main/java/com/xujie/sys/modules/erf/mapper/ErfExpApplyMapper.java b/src/main/java/com/xujie/sys/modules/erf/mapper/ErfExpApplyMapper.java
index deef8aa7..a208666a 100644
--- a/src/main/java/com/xujie/sys/modules/erf/mapper/ErfExpApplyMapper.java
+++ b/src/main/java/com/xujie/sys/modules/erf/mapper/ErfExpApplyMapper.java
@@ -121,4 +121,21 @@ public interface ErfExpApplyMapper extends BaseMapper<ErfExpApply> {
      */
     int updateAttachmentWorkOrderNo(@Param("applyNo") String applyNo,
                                    @Param("workOrderNo") String workOrderNo);
+
+    /** 更新主表的试验单号（主键变更专用，用旧值定位） */
+    void updateMainApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateFlowInstanceApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateFlowNodeInstanceApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateFlowApproveLogApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateTriConfirmApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateTriConfirmDetailApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateRawMaterialApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
+
+    void updateOssApplyNo(@Param("oldApplyNo") String oldApplyNo, @Param("newApplyNo") String newApplyNo);
 }
diff --git a/src/main/java/com/xujie/sys/modules/erf/service/impl/ErfExpApplyServiceImpl.java b/src/main/java/com/xujie/sys/modules/erf/service/impl/ErfExpApplyServiceImpl.java
index e52cdd35..1da7166f 100644
--- a/src/main/java/com/xujie/sys/modules/erf/service/impl/ErfExpApplyServiceImpl.java
+++ b/src/main/java/com/xujie/sys/modules/erf/service/impl/ErfExpApplyServiceImpl.java
@@ -102,27 +102,54 @@ public class ErfExpApplyServiceImpl extends ServiceImpl<ErfExpApplyMapper, ErfEx
 
     @Override
     public String saveExpApply(ErfExpApplyData data) {
+        if (data.getApplyNo() == null || data.getApplyNo().trim().isEmpty()) {
+            throw new XJException("请输入试验单号");
+        }
+
+        String newApplyNo = data.getApplyNo().trim();
+        String originalApplyNo = data.getOriginalApplyNo();
+        boolean isNew = (originalApplyNo == null || originalApplyNo.trim().isEmpty());
+
         ErfExpApply entity = new ErfExpApply();
         BeanUtils.copyProperties(data, entity);
+        entity.setApplyNo(newApplyNo);
 
-        if (data.getApplyNo() == null || data.getApplyNo().isEmpty()) {
-            // 新增 - 生成申请单号（createTime和updateTime由MyBatis-Plus自动填充）
-            String applyNo = generateApplyNo(data.getBuNo().split("-").length>1?data.getBuNo().split("-")[1]:data.getBuNo());
-            entity.setApplyNo(applyNo);
+        if (isNew) {
+            // 新增
             entity.setStatus("草稿");
             entity.setCreateTime(new Date());
             entity.setUpdateTime(new Date());
             String site = erfExpApplyMapper.getSiteByBu(data.getBuNo());
             entity.setSite(site);
             this.save(entity);
-            log.info("新增工程实验申请单: {}", applyNo);
-            return applyNo;
+            log.info("新增工程实验申请单: {}", newApplyNo);
         } else {
+            // 修改 - 通过原始单号查找记录
+            originalApplyNo = originalApplyNo.trim();
+            ErfExpApply existing = this.getById(originalApplyNo);
+            if (existing == null) {
+                throw new XJException("申请单不存在: " + originalApplyNo);
+            }
             entity.setUpdateTime(new Date());
+            if (!newApplyNo.equals(originalApplyNo)) {
+                // 试验单号发生变更：
+                // 第一步：级联更新所有关联表（Druid防注入不允许多语句，逐条执行）
+                log.info("试验单号变更: {} -> {}", originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateFlowInstanceApplyNo(originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateFlowNodeInstanceApplyNo(originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateFlowApproveLogApplyNo(originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateTriConfirmApplyNo(originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateTriConfirmDetailApplyNo(originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateRawMaterialApplyNo(originalApplyNo, newApplyNo);
+                erfExpApplyMapper.updateOssApplyNo(originalApplyNo, newApplyNo);
+                // 第二步：更新主表主键（用旧值定位，改为新值）
+                erfExpApplyMapper.updateMainApplyNo(originalApplyNo, newApplyNo);
+            }
+            // 第三步：更新主表其他字段（此时主键已是新值，updateById可正确定位）
             this.updateById(entity);
-            log.info("修改工程实验申请单: {}", entity.getApplyNo());
-            return entity.getApplyNo();
+            log.info("修改工程实验申请单: {} (原单号: {})", newApplyNo, originalApplyNo);
         }
+        return newApplyNo;
     }
 
     @Override
@@ -1507,12 +1534,12 @@ public class ErfExpApplyServiceImpl extends ServiceImpl<ErfExpApplyMapper, ErfEx
         return "<table border='1' cellpadding='6' cellspacing='0' "
             + "style='border-collapse:collapse; width:100%; font-size:13px;'>"
             + "<thead style='background-color:#2196F3; color:white;'><tr>"
-            + "<th>收到邮件日期</th><th>项目号</th><th>实验单号</th><th>项目名称</th>"
+            + "<th>收到邮件日期</th><th>项目号</th><th>试验单号</th><th>项目名称</th>"
             + "<th>安排生产工序</th><th>数量</th><th>备注</th><th>需求日期</th><th>工程师</th>"
             + "</tr></thead><tbody><tr>"
             + "<td>" + todayStr + "</td>"
             + "<td>" + (entity.getProjectNo() != null ? entity.getProjectNo() : "") + "</td>"
-            + "<td>" + (entity.getWorkOrderNo()!=null ? entity.getWorkOrderNo() : "") + "</td>"
+            + "<td>" + (entity.getApplyNo()!=null ? entity.getApplyNo() : "") + "</td>"
             + "<td>" + (entity.getTitle() != null ? entity.getTitle() : "") + "</td>"
             + "<td>" + (entity.getProcessRequirement() != null ? entity.getProcessRequirement() : "") + "</td>"
             + "<td>" + (entity.getQuantityReq() != null ? entity.getQuantityReq() : "") + "</td>"
diff --git a/src/main/resources/mapper/erf/ErfExpApplyMapper.xml b/src/main/resources/mapper/erf/ErfExpApplyMapper.xml
index fc0db588..4db0366b 100644
--- a/src/main/resources/mapper/erf/ErfExpApplyMapper.xml
+++ b/src/main/resources/mapper/erf/ErfExpApplyMapper.xml
@@ -466,4 +466,36 @@
         )
     </insert>
 
+    <update id="updateMainApplyNo">
+        UPDATE erf_exp_apply SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateFlowInstanceApplyNo">
+        UPDATE erf_flow_instance SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateFlowNodeInstanceApplyNo">
+        UPDATE erf_flow_node_instance SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateFlowApproveLogApplyNo">
+        UPDATE erf_flow_approve_log SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateTriConfirmApplyNo">
+        UPDATE erf_exp_tri_confirm SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateTriConfirmDetailApplyNo">
+        UPDATE erf_exp_tri_confirm_detail SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateRawMaterialApplyNo">
+        UPDATE erf_exp_raw_material SET apply_no = #{newApplyNo} WHERE apply_no = #{oldApplyNo}
+    </update>
+
+    <update id="updateOssApplyNo">
+        UPDATE sys_oss SET order_ref2 = #{newApplyNo} WHERE order_ref2 = #{oldApplyNo} AND order_ref1 = 'ERF'
+    </update>
+
 </mapper>