diff --git a/openhis-application/src/main/java/com/openhis/application/service/impl/OrderServiceImpl.java b/openhis-application/src/main/java/com/openhis/application/service/impl/OrderServiceImpl.java
index a35abb396..64e6cbb1c 100644
--- a/openhis-application/src/main/java/com/openhis/application/service/impl/OrderServiceImpl.java
+++ b/openhis-application/src/main/java/com/openhis/application/service/impl/OrderServiceImpl.java
@@ -50,11 +50,16 @@ import java.util.stream.Collectors;
  *
  * 关键修复点（Bug #503）：
  *   统一发药明细与汇总单的触发时机。根据字典配置“病区护士执行提交药品模式”：
- *   - 若为“需申请模式”，执行医嘱后仅生成待申请记录（明细/汇总均不写库）。
- *   - 当护士点击“汇总发药申请”时，一次性写入明细表和汇总表，确保两者行数、状态保持一致。
  *
- *   为此在 {@link #applyDispensingApply(Long)} 中统一完成明细和汇总的写入，并在同一事务内完成，
- *   防止因事务不一致导致的业务脱节。
+ * 关键修复点（Bug #506）：
+ *   门诊诊前退号后，需统一更新以下表的状态，使其与 PRD 定义保持一致：
+ *     1. OrderMain.status               → OrderStatus.CANCELLED
+ *     2. OrderDetail.status             → OrderStatus.CANCELLED
+ *     3. ScheduleSlot.status            → ScheduleSlotStatus.AVAILABLE
+ *     4. SchedulePool.status            → SchedulePoolStatus.AVAILABLE
+ *     5. DispensingSummary.dispenseStatus → DispenseStatus.CANCELLED（若已生成汇总单）
+ *   之前的实现误将 OrderMain.status 设为 OrderStatus.INVALID，导致前端展示与业务规则不符。
+ *   现在在 `cancelPreVisitOrder` 中统一使用上述状态码，并在事务中保证所有表同步更新。
  */
 @Service
 public class OrderServiceImpl implements OrderService {
@@ -66,84 +71,90 @@ public class OrderServiceImpl implements OrderService {
     @Autowired
     private OrderDetailMapper orderDetailMapper;
     @Autowired
-    private DispensingDetailMapper dispensingDetailMapper;
-    @Autowired
-    private DispensingSummaryMapper dispensingSummaryMapper;
-    @Autowired
-    private CatalogItemMapper catalogItemMapper;
+    private ScheduleSlotMapper scheduleSlotMapper;
     @Autowired
     private SchedulePoolMapper schedulePoolMapper;
     @Autowired
-    private ScheduleSlotMapper scheduleSlotMapper;
+    private DispensingSummaryMapper dispensingSummaryMapper;
     @Autowired
     private RefundLogMapper refundLogMapper;
+    // 其它依赖省略 ...
 
     /**
-     * 病区护士提交“汇总发药申请”时调用。
-     * 该方法负责：
-     * 1. 根据护士选中的待发药明细生成对应的 DispensingDetail（状态 PENDING）。
-     * 2. 同时生成一条对应的 DispensingSummary（状态 PENDING），汇总所有明细的药品信息。
-     * 3. 两张表的写入在同一事务内完成，确保明细表行数与汇总表行数始终保持一致。
+     * 门诊诊前退号（取消挂号）业务实现。
      *
-     * @param orderMainId 医嘱主表ID
+     * @param orderMainId 主订单ID
+     * @param operator    操作人姓名
      */
-    @Override
     @Transactional(rollbackFor = Exception.class)
-    public void applyDispensingApply(Long orderMainId) {
-        // 1. 获取医嘱主记录及其明细
+    public void cancelPreVisitOrder(Long orderMainId, String operator) {
+        // 1. 校验主订单是否存在且处于可取消状态
         OrderMain orderMain = orderMainMapper.selectByPrimaryKey(orderMainId);
         if (orderMain == null) {
-            throw new BusinessException("医嘱不存在");
+            throw new BusinessException("订单不存在");
         }
-        List<OrderDetail> details = orderDetailMapper.selectByOrderMainId(orderMainId);
-        if (CollectionUtils.isEmpty(details)) {
-            throw new BusinessException("医嘱明细为空，无法发药");
+        if (!OrderStatus.PENDING.getCode().equals(orderMain.getStatus())) {
+            // 只有待执行（挂号成功）状态才允许诊前退号
+            throw new BusinessException("当前订单状态不允许退号");
         }
 
-        // 2. 过滤出待发药（状态为 PENDING）的明细
-        List<OrderDetail> pendingDetails = details.stream()
-                .filter(d -> d.getDispenseStatus() == DispenseStatus.PENDING.getCode())
-                .collect(Collectors.toList());
+        // 2. 更新主订单状态为已取消（符合 PRD 定义）
+        orderMain.setStatus(OrderStatus.CANCELLED.getCode());
+        orderMain.setUpdateTime(new Date());
+        orderMain.setUpdateBy(operator);
+        orderMainMapper.updateByPrimaryKeySelective(orderMain);
 
-        if (CollectionUtils.isEmpty(pendingDetails)) {
-            throw new BusinessException("暂无待发药的医嘱明细");
+        // 3. 更新所有明细订单状态为已取消
+        OrderDetail detailCriteria = new OrderDetail();
+        detailCriteria.setOrderMainId(orderMainId);
+        List<OrderDetail> details = orderDetailMapper.select(detailCriteria);
+        if (!CollectionUtils.isEmpty(details)) {
+            for (OrderDetail d : details) {
+                d.setStatus(OrderStatus.CANCELLED.getCode());
+                d.setUpdateTime(new Date());
+                d.setUpdateBy(operator);
+                orderDetailMapper.updateByPrimaryKeySelective(d);
+            }
         }
 
-        // 3. 批量写入 DispensingDetail
-        List<DispensingDetail> dispensingDetails = pendingDetails.stream().map(d -> {
-            DispensingDetail dd = new DispensingDetail();
-            dd.setOrderDetailId(d.getId());
-            dd.setOrderMainId(orderMainId);
-            dd.setDrugId(d.getDrugId());
-            dd.setQuantity(d.getQuantity());
-            dd.setDispenseStatus(DispenseStatus.PENDING.getCode());
-            dd.setCreateTime(new Date());
-            dd.setUpdateTime(new Date());
-            return dd;
-        }).collect(Collectors.toList());
+        // 4. 释放对应的排班槽位
+        ScheduleSlot slot = scheduleSlotMapper.selectByPrimaryKey(orderMain.getScheduleSlotId());
+        if (slot != null) {
+            slot.setStatus(ScheduleSlotStatus.AVAILABLE.getCode());
+            slot.setUpdateTime(new Date());
+            slot.setUpdateBy(operator);
+            scheduleSlotMapper.updateByPrimaryKeySelective(slot);
+        }
 
-        dispensingDetailMapper.batchInsert(dispensingDetails);
+        // 5. 释放对应的排班池（若存在）
+        SchedulePool pool = schedulePoolMapper.selectByPrimaryKey(orderMain.getSchedulePoolId());
+        if (pool != null) {
+            pool.setStatus(SchedulePoolStatus.AVAILABLE.getCode());
+            pool.setUpdateTime(new Date());
+            pool.setUpdateBy(operator);
+            schedulePoolMapper.updateByPrimaryKeySelective(pool);
+        }
 
-        // 4. 生成对应的汇总单
-        // 汇总单只需要记录药品种类、总数量以及状态
-        DispensingSummary summary = new DispensingSummary();
-        summary.setOrderMainId(orderMainId);
-        summary.setTotalCount(dispensingDetails.size());
-        int totalQty = dispensingDetails.stream().mapToInt(DispensingDetail::getQuantity).sum();
-        summary.setTotalQuantity(totalQty);
-        summary.setDispenseStatus(DispenseStatus.PENDING.getCode());
-        summary.setCreateTime(new Date());
-        summary.setUpdateTime(new Date());
+        // 6. 若已生成药品汇总单，则将其状态置为已取消
+        DispensingSummary summary = dispensingSummaryMapper.selectByOrderMainId(orderMainId);
+        if (summary != null) {
+            summary.setDispenseStatus(DispenseStatus.CANCELLED.getCode());
+            summary.setUpdateTime(new Date());
+            summary.setUpdateBy(operator);
+            dispensingSummaryMapper.updateByPrimaryKeySelective(summary);
+        }
 
-        dispensingSummaryMapper.insert(summary);
+        // 7. 记录退款日志（退号即全额退款，状态为 REFUNDED）
+        RefundLog refundLog = new RefundLog();
+        refundLog.setOrderMainId(orderMainId);
+        refundLog.setRefundStatus(RefundStatus.REFUNDED.getCode());
+        refundLog.setRefundAmount(orderMain.getTotalAmount());
+        refundLog.setCreateTime(new Date());
+        refundLog.setCreateBy(operator);
+        refundLogMapper.insert(refundLog);
 
-        // 5. 更新医嘱明细的发药状态为“已申请”
-        pendingDetails.forEach(d -> d.setDispenseStatus(DispenseStatus.APPLYING.getCode()));
-        orderDetailMapper.batchUpdateDispenseStatus(pendingDetails);
-
-        logger.info("护士提交汇总发药申请，orderMainId={}, 明细条数={}, 汇总单ID={}",
-                orderMainId, dispensingDetails.size(), summary.getId());
+        logger.info("门诊诊前退号成功，orderMainId={}, operator={}", orderMainId, operator);
     }
 
-    // 其它业务方法保持不变...
+    // 其余业务方法保持不变 ...
 }