diff --git a/firstleg/src/main/java/com/baiyue/firstleg/service/ContainerService.java b/firstleg/src/main/java/com/baiyue/firstleg/service/ContainerService.java
index 543e821a1..7d56977ec 100644
--- a/firstleg/src/main/java/com/baiyue/firstleg/service/ContainerService.java
+++ b/firstleg/src/main/java/com/baiyue/firstleg/service/ContainerService.java
@@ -79,14 +79,20 @@ public class ContainerService {
     public ContainerBookingEntity linkOceanBooking(long id, long operatorId, String operatorName, OceanBookingLinkRequest request) {
         ContainerBookingEntity container = required(id); requireVersion(container, request.expectedVersion()); requireFirstLinkMutable(container);
         if (container.getOceanBookingId() != null) throw conflict("模拟柜已关联真实订舱柜");
+        String existingContainerNo = trim(container.getContainerNo());
+        String requestedContainerNo = trim(request.containerNo());
+        String containerNo = requestedContainerNo == null
+            ? existingContainerNo
+            : Iso6346ContainerNumber.require(requestedContainerNo);
+        if (existingContainerNo != null && !existingContainerNo.equals(containerNo)) {
+            throw conflict("输入的真实集装箱号与当前柜次已录入柜号不一致，请先在预装运输信息中纠正");
+        }
         OceanBookingEntity booking = oceanBookings.find(request.oceanBookingId());
         if (booking == null || !"RELEASED".equals(booking.getStatus())) throw conflict("只能关联已发布订舱");
         OceanBookingContainerRequirementEntity requirement = oceanBookings.requirement(request.oceanBookingId(), request.requirementId());
         if (requirement == null) throw new BizException(ResultCode.NOT_FOUND, "订舱箱型需求不存在");
         long allocated = oceanBookings.activeLinkedCount(request.oceanBookingId(), request.requirementId());
         if (allocated >= requirement.getQuantity()) throw conflict("该订舱箱型需求已达到数量上限");
-        String requestedContainerNo = trim(request.containerNo());
-        String containerNo = requestedContainerNo == null ? null : Iso6346ContainerNumber.require(requestedContainerNo);
         if (containerNo != null && repository.containerNoExists(containerNo, id)) throw conflict("集装箱号已存在");
         if (!java.util.Objects.equals(container.getWarehouseId(), booking.getWarehouseId())
             || !java.util.Objects.equals(container.getChannelGroupCode(), booking.getChannelCode())
@@ -134,7 +140,6 @@ public class ContainerService {
     private void requireFirstLinkMutable(ContainerBookingEntity container) {
         SmartLoadingStatus value = status(container);
         if ((value != SmartLoadingStatus.WAIT_LOADING && value != SmartLoadingStatus.EDITING)
-            || trim(container.getContainerNo()) != null
             || repository.hasPickTask(container.getId()) || repository.hasEvidence(container.getId())
             || repository.hasDocuments(container.getId())) throw conflict("已进入PDA、证据、单证或不可逆装柜阶段，不能关联订舱");
     }
diff --git a/firstleg/src/test/java/com/baiyue/firstleg/service/ContainerServiceTest.java b/firstleg/src/test/java/com/baiyue/firstleg/service/ContainerServiceTest.java
index 36662a340..5be2b2072 100644
--- a/firstleg/src/test/java/com/baiyue/firstleg/service/ContainerServiceTest.java
+++ b/firstleg/src/test/java/com/baiyue/firstleg/service/ContainerServiceTest.java
@@ -252,6 +252,39 @@ class ContainerServiceTest {
         verify(oceanBookings).insert(any(OceanBookingContainerAllocationEntity.class));
     }
 
+    @Test
+    @DisplayName("预装已录入真实柜号时关联订舱保留原柜号")
+    void linksReleasedBookingWhilePreservingExistingRealContainerNumber() {
+        ContainerBookingEntity container = stubLinkContext();
+        container.setContainerNo("MSCU6639870");
+        when(repository.find(11L)).thenReturn(container, container);
+        when(repository.linkReleasedBooking(eq(11L), eq(21L), eq(31L), eq("MSCU6639870"),
+            any(OceanBookingEntity.class), eq(2), eq(9L), eq("admin"))).thenReturn(1);
+
+        ContainerBookingEntity result = service.linkOceanBooking(11L, 9L, "admin",
+            new OceanBookingLinkRequest(21L, 31L, null, 2));
+
+        assertThat(result.getContainerNo()).isEqualTo("MSCU6639870");
+        verify(repository).linkReleasedBooking(eq(11L), eq(21L), eq(31L), eq("MSCU6639870"),
+            any(OceanBookingEntity.class), eq(2), eq(9L), eq("admin"));
+        verify(oceanBookings).insert(any(OceanBookingContainerAllocationEntity.class));
+    }
+
+    @Test
+    @DisplayName("关联订舱时拒绝用不同柜号覆盖预装已录入柜号")
+    void rejectsDifferentRealContainerNumberWhenLinkingReleasedBooking() {
+        ContainerBookingEntity container = stubLinkContext();
+        container.setContainerNo("MSCU6639870");
+
+        assertThatThrownBy(() -> service.linkOceanBooking(11L, 9L, "admin",
+            new OceanBookingLinkRequest(21L, 31L, "TSTU1503306", 2)))
+            .isInstanceOf(BizException.class).hasMessageContaining("与当前柜次已录入柜号不一致");
+
+        verify(repository, never()).linkReleasedBooking(anyLong(), anyLong(), anyLong(), anyString(),
+            any(), anyInt(), anyLong(), anyString());
+        verifyNoInteractions(oceanBookings);
+    }
+
     @Test
     @DisplayName("提柜后按柜次版本原子补录真实柜号")
     void assignsRealContainerNumberAfterPickup() {
@@ -436,7 +469,7 @@ class ContainerServiceTest {
             any(), anyInt(), anyLong(), anyString());
     }
 
-    private void stubLinkContext() {
+    private ContainerBookingEntity stubLinkContext() {
         ContainerBookingEntity container = booking("WAIT_LOADING", 2);
         container.setContainerNo(null);
         container.setWarehouseId(101L); container.setChannelGroupCode("MATSON_CLX"); container.setChannelCode(null);
@@ -450,6 +483,7 @@ class ContainerServiceTest {
         when(oceanBookings.find(21L)).thenReturn(oceanBooking);
         when(oceanBookings.requirement(21L, 31L)).thenReturn(requirement);
         when(oceanBookings.activeLinkedCount(21L, 31L)).thenReturn(0L);
+        return container;
     }
 
     @Test