diff --git a/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadGroupMapper.java b/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadGroupMapper.java
index 05ba5ffdf..6bc428f35 100644
--- a/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadGroupMapper.java
+++ b/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadGroupMapper.java
@@ -14,9 +14,11 @@ import static com.baiyue.firstleg.loading.coload.persistence.ColoadPersistenceRo
 @Mapper
 public interface ColoadGroupMapper {
     @Select({"<script>", """
-        SELECT o.tenant_id tenantId,o.order_id orderId,o.id inboundId,
-               o.process_status processStatus,o.warehouse_id warehouseId,
-               o.channel_code channelCode,o.total_package_count fullPackageCount,
+        SELECT o.tenant_id tenantId,o.order_id orderId,o.order_no orderNo,
+               o.id inboundId,o.inbound_code inboundCode,o.process_status processStatus,
+               o.warehouse_id warehouseId,o.warehouse_name warehouseName,
+               o.channel_code channelCode,o.channel_name channelName,
+               o.total_package_count fullPackageCount,
                (SELECT COUNT(*) FROM fl_loading_plan_item item
                  WHERE item.account_id=o.tenant_id AND item.inbound_id=o.id AND item.deleted=0)
                  activeAllocationCount,
diff --git a/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadPersistenceRows.java b/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadPersistenceRows.java
index ddd017b36..4ea52edc5 100644
--- a/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadPersistenceRows.java
+++ b/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/persistence/ColoadPersistenceRows.java
@@ -15,10 +15,14 @@ public final class ColoadPersistenceRows {
     public static class InboundCandidateRow {
         private Long tenantId;
         private Long orderId;
+        private String orderNo;
         private Long inboundId;
+        private String inboundCode;
         private String processStatus;
         private Long warehouseId;
+        private String warehouseName;
         private String channelCode;
+        private String channelName;
         private Integer fullPackageCount;
         private Integer activeAllocationCount;
         private Long activeGroupId;
diff --git a/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/service/ColoadGroupService.java b/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/service/ColoadGroupService.java
index 03c78c764..369717a2c 100644
--- a/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/service/ColoadGroupService.java
+++ b/firstleg/src/main/java/com/baiyue/firstleg/loading/coload/service/ColoadGroupService.java
@@ -237,35 +237,55 @@ public class ColoadGroupService implements ColoadGroupAssignmentPort {
             .computeIfAbsent(row.getOrderId(), ignored -> new ArrayList<>()).add(row));
         List<InboundCandidateRow> resolved = new ArrayList<>();
         for (Long orderId : orderIds) {
-            List<InboundCandidateRow> eligible = byOrder.getOrDefault(orderId, List.of()).stream()
-                .filter(row -> eligible(row, allowedGroupId)).toList();
+            List<InboundCandidateRow> rows = byOrder.getOrDefault(orderId, List.of());
+            if (rows.isEmpty()) throw conflict("所选订单不存在或已失效");
+            List<InboundCandidateRow> eligible = rows.stream()
+                .filter(row -> unavailableReason(row, allowedGroupId) == null).toList();
             if (eligible.isEmpty()) {
-                throw conflict("订单 " + orderId + " 不存在可创建同柜不可拆组的可用入库片段");
+                String order = StringUtils.hasText(rows.get(0).getOrderNo())
+                    ? "订单“" + rows.get(0).getOrderNo().trim() + "”" : "所选订单";
+                String reasons = rows.stream().map(row -> candidateLabel(row) + unavailableReason(row, allowedGroupId))
+                    .distinct().limit(10).collect(java.util.stream.Collectors.joining("；"));
+                throw conflict(order + "当前没有可建组的入仓片段：" + reasons);
             }
             resolved.addAll(eligible);
         }
         return resolved;
     }
 
-    private boolean eligible(InboundCandidateRow row, Long allowedGroupId) {
-        return row.getTenantId() != null && row.getTenantId() > 0
-            && row.getInboundId() != null && row.getInboundId() > 0
-            && "WAIT_SPLIT".equals(row.getProcessStatus())
-            && row.getFullPackageCount() != null && row.getFullPackageCount() > 0
-            && Objects.equals(row.getActiveAllocationCount(), 0)
-            && (row.getActiveGroupId() == null || Objects.equals(row.getActiveGroupId(), allowedGroupId));
+    private String unavailableReason(InboundCandidateRow row, Long allowedGroupId) {
+        if (row.getTenantId() == null || row.getTenantId() <= 0
+            || row.getInboundId() == null || row.getInboundId() <= 0
+            || !StringUtils.hasText(row.getInboundCode())) return "权威业务快照缺失";
+        if (!"WAIT_SPLIT".equals(row.getProcessStatus())) return "状态非待分柜";
+        if (!Objects.equals(row.getActiveAllocationCount(), 0)) return "已分配装柜计划";
+        if (row.getActiveGroupId() != null && !Objects.equals(row.getActiveGroupId(), allowedGroupId)) {
+            return "已在其他同柜组";
+        }
+        if (row.getFullPackageCount() == null || row.getFullPackageCount() <= 0) return "箱数无效";
+        if (row.getWarehouseId() == null || row.getWarehouseId() <= 0
+            || !StringUtils.hasText(row.getWarehouseName())) return "缺少平台收货仓权威快照";
+        if (!StringUtils.hasText(row.getChannelCode()) || !StringUtils.hasText(row.getChannelName())) {
+            return "缺少渠道权威快照";
+        }
+        return null;
+    }
+
+    private static String candidateLabel(InboundCandidateRow row) {
+        return StringUtils.hasText(row.getInboundCode())
+            ? "入仓码“" + row.getInboundCode().trim() + "”" : "入仓码缺失的片段";
     }
 
     private void validateSameRoute(List<InboundCandidateRow> rows) {
         InboundCandidateRow first = rows.get(0);
-        if (first.getWarehouseId() == null || first.getWarehouseId() <= 0
-            || !StringUtils.hasText(first.getChannelCode())) {
-            throw conflict("订单缺少国内仓或渠道权威快照");
-        }
         for (InboundCandidateRow row : rows) {
-            if (!Objects.equals(first.getWarehouseId(), row.getWarehouseId())
-                || !normalized(first.getChannelCode()).equals(normalized(row.getChannelCode()))) {
-                throw conflict("同柜不可拆组成员必须属于同一国内仓和渠道");
+            if (!Objects.equals(first.getWarehouseId(), row.getWarehouseId())) {
+                throw conflict(candidateLabel(first) + "（" + first.getWarehouseName() + "）与"
+                    + candidateLabel(row) + "（" + row.getWarehouseName() + "）平台收货仓不同");
+            }
+            if (!normalized(first.getChannelCode()).equals(normalized(row.getChannelCode()))) {
+                throw conflict(candidateLabel(first) + "（" + first.getChannelName() + "）与"
+                    + candidateLabel(row) + "（" + row.getChannelName() + "）渠道不同");
             }
         }
     }
@@ -360,11 +380,11 @@ public class ColoadGroupService implements ColoadGroupAssignmentPort {
     }
 
     private static List<Long> normalizedOrderIds(List<Long> source, int minimum, int maximum) {
-        if (source == null) throw badRequest("orderIds不能为空");
+        if (source == null) throw badRequest("请选择需要设置为同柜不可拆组的订单");
         List<Long> values = source.stream().filter(Objects::nonNull).distinct().sorted().toList();
         if (values.size() != source.size() || values.size() < minimum || values.size() > maximum
             || values.stream().anyMatch(value -> value <= 0)) {
-            throw badRequest("orderIds数量、重复项或ID值不合法");
+            throw badRequest("请选择" + minimum + "至" + maximum + "个不同的有效订单");
         }
         return values;
     }
diff --git a/firstleg/src/main/resources/openapi/coload-groups-v1.yaml b/firstleg/src/main/resources/openapi/coload-groups-v1.yaml
index af59d801f..577859844 100644
--- a/firstleg/src/main/resources/openapi/coload-groups-v1.yaml
+++ b/firstleg/src/main/resources/openapi/coload-groups-v1.yaml
@@ -10,6 +10,9 @@ paths:
       description: >-
         需要 platform:firstleg:smart-loading:assign。orderIds 至少2项；服务端解析每个订单全部 WAIT_SPLIT、
         未分配且未属于其他活动组的可用入库片段，要求国内仓和渠道一致，并冻结全部片段及其满箱数。
+        同一订单部分片段不可用时只纳入全部当前可用片段；全部不可用时按入仓码明确返回状态非待分柜、
+        已分配装柜计划、已在其他同柜组、箱数无效或仓库/渠道权威快照缺失。跨成员仓库或渠道不一致时
+        返回入仓码及仓库名/渠道名；平台错误不得展示 orderId、inboundId 或 groupId。
       parameters:
         - $ref: '#/components/parameters/IdempotencyKey'
       requestBody:
diff --git a/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupOpenApiContractTest.java b/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupOpenApiContractTest.java
index a722e1eea..5b74f9424 100644
--- a/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupOpenApiContractTest.java
+++ b/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupOpenApiContractTest.java
@@ -41,6 +41,10 @@ class ColoadGroupOpenApiContractTest {
             .contains("任一冻结成员缺少有效 inboundCode 时失败关闭")
             .contains("全部 WAIT_SPLIT")
             .contains("国内仓和渠道一致")
+            .contains("状态非待分柜")
+            .contains("已分配装柜计划")
+            .contains("已在其他同柜组")
+            .contains("平台错误不得展示 orderId、inboundId 或 groupId")
             .doesNotContain("destinationType")
             .doesNotContain("destinationWarehouseId")
             .doesNotContain("destinationCode")
diff --git a/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupServiceTest.java b/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupServiceTest.java
index 6271b8555..07e46b5f3 100644
--- a/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupServiceTest.java
+++ b/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupServiceTest.java
@@ -123,9 +123,11 @@ class ColoadGroupServiceTest {
 
     @Test
     void createsCrossCustomerGroupAndFreezesAllAvailableFragmentsForEveryOrder() {
+        InboundCandidateRow alreadyAllocatedFragment = candidate(101L, 11L, 1004L, 40);
+        alreadyAllocatedFragment.setActiveAllocationCount(1);
         when(mapper.lockCandidates(List.of(11L, 12L))).thenReturn(List.of(
             candidate(101L, 11L, 1001L, 30), candidate(101L, 11L, 1003L, 20),
-            candidate(202L, 12L, 1002L, 50)));
+            alreadyAllocatedFragment, candidate(202L, 12L, 1002L, 50)));
         when(mapper.insertGroup(anyLong(), anyString(), eq(9L), eq("CH"),
             eq(7L), eq("operator"))).thenReturn(1);
         when(mapper.insertMember(anyLong(), anyLong(), anyLong(), anyLong(), anyLong(), anyInt()))
@@ -152,13 +154,16 @@ class ColoadGroupServiceTest {
         verify(mapper).insertMember(anyLong(), eq(groupId.getValue()), eq(101L), eq(11L), eq(1001L), eq(30));
         verify(mapper).insertMember(anyLong(), eq(groupId.getValue()), eq(101L), eq(11L), eq(1003L), eq(20));
         verify(mapper).insertMember(anyLong(), eq(groupId.getValue()), eq(202L), eq(12L), eq(1002L), eq(50));
+        verify(mapper, never()).insertMember(anyLong(), eq(groupId.getValue()), eq(101L), eq(11L),
+            eq(1004L), anyInt());
     }
 
     @Test
     void rejectsSingleOrderBeforeAnyDatabaseWrite() {
         assertThatThrownBy(() -> service.create(List.of(11L), "key", 7L, "operator"))
             .isInstanceOf(BizException.class)
-            .hasMessageContaining("orderIds");
+            .hasMessageContaining("请选择2至100个不同的有效订单")
+            .hasMessageNotContaining("orderId");
         verify(mapper, never()).insertCommand(anyLong(), anyLong(), anyString(), anyString(), anyString());
     }
 
@@ -173,7 +178,11 @@ class ColoadGroupServiceTest {
 
         assertThatThrownBy(() -> service.create(List.of(11L, 12L), "key", 7L, "operator"))
             .isInstanceOf(BizException.class)
-            .hasMessageContaining("不存在可创建");
+            .hasMessageContaining("订单“FO-11”")
+            .hasMessageContaining("入仓码“IN-1001”已分配装柜计划")
+            .hasMessageNotContaining("订单 11")
+            .hasMessageNotContaining("groupId")
+            .hasMessageNotContaining("inboundId");
         verify(mapper, never()).insertGroup(anyLong(), anyString(), anyLong(), anyString(),
             anyLong(), any());
     }
@@ -182,14 +191,51 @@ class ColoadGroupServiceTest {
     void rejectsDifferentWarehouseOrChannel() {
         InboundCandidateRow second = candidate(202L, 12L, 1002L, 50);
         second.setWarehouseId(10L);
-        when(mapper.insertCommand(anyLong(), eq(7L), eq("CREATE"), eq("route-key"), anyString()))
+        second.setWarehouseName("东莞仓");
+        when(mapper.insertCommand(anyLong(), eq(7L), eq("CREATE"), anyString(), anyString()))
             .thenReturn(1);
         when(mapper.lockCandidates(List.of(11L, 12L))).thenReturn(List.of(
             candidate(101L, 11L, 1001L, 30), second));
 
         assertThatThrownBy(() -> service.create(List.of(11L, 12L), "route-key", 7L, "operator"))
             .isInstanceOf(BizException.class)
-            .hasMessageContaining("同一国内仓和渠道");
+            .hasMessageContaining("入仓码“IN-1001”（义乌仓）")
+            .hasMessageContaining("入仓码“IN-1002”（东莞仓）")
+            .hasMessageContaining("平台收货仓不同");
+
+        InboundCandidateRow otherChannel = candidate(202L, 12L, 1002L, 50);
+        otherChannel.setChannelCode("EXX"); otherChannel.setChannelName("EXX海卡");
+        when(mapper.lockCandidates(List.of(11L, 12L))).thenReturn(List.of(
+            candidate(101L, 11L, 1001L, 30), otherChannel));
+        assertThatThrownBy(() -> service.create(List.of(11L, 12L), "channel-key", 7L, "operator"))
+            .isInstanceOf(BizException.class)
+            .hasMessageContaining("入仓码“IN-1001”（美森海卡）")
+            .hasMessageContaining("入仓码“IN-1002”（EXX海卡）")
+            .hasMessageContaining("渠道不同");
+    }
+
+    @Test
+    void reportsEveryUnavailableReasonUsingBusinessIdentifiers() {
+        when(mapper.insertCommand(anyLong(), eq(7L), eq("CREATE"), anyString(), anyString()))
+            .thenReturn(1);
+        InboundCandidateRow status = candidate(101L, 11L, 1001L, 30);
+        status.setProcessStatus("LOADING");
+        assertUnavailable(status, "state-key", "状态非待分柜");
+
+        InboundCandidateRow grouped = candidate(101L, 11L, 1001L, 30);
+        grouped.setActiveGroupId(900L);
+        assertUnavailable(grouped, "group-key", "已在其他同柜组");
+
+        InboundCandidateRow boxes = candidate(101L, 11L, 1001L, 0);
+        assertUnavailable(boxes, "boxes-key", "箱数无效");
+
+        InboundCandidateRow warehouse = candidate(101L, 11L, 1001L, 30);
+        warehouse.setWarehouseName(" ");
+        assertUnavailable(warehouse, "warehouse-key", "缺少平台收货仓权威快照");
+
+        InboundCandidateRow channel = candidate(101L, 11L, 1001L, 30);
+        channel.setChannelName(null);
+        assertUnavailable(channel, "channel-key", "缺少渠道权威快照");
     }
 
     @Test
@@ -342,12 +388,25 @@ class ColoadGroupServiceTest {
 
     private static InboundCandidateRow candidate(long tenantId, long orderId, long inboundId, int packages) {
         InboundCandidateRow value = new InboundCandidateRow();
-        value.setTenantId(tenantId); value.setOrderId(orderId); value.setInboundId(inboundId);
-        value.setProcessStatus("WAIT_SPLIT"); value.setWarehouseId(9L); value.setChannelCode("CH");
+        value.setTenantId(tenantId); value.setOrderId(orderId); value.setOrderNo("FO-" + orderId);
+        value.setInboundId(inboundId); value.setInboundCode("IN-" + inboundId);
+        value.setProcessStatus("WAIT_SPLIT"); value.setWarehouseId(9L); value.setWarehouseName("义乌仓");
+        value.setChannelCode("CH"); value.setChannelName("美森海卡");
         value.setFullPackageCount(packages); value.setActiveAllocationCount(0);
         return value;
     }
 
+    private void assertUnavailable(InboundCandidateRow row, String key, String reason) {
+        when(mapper.lockCandidates(List.of(11L, 12L))).thenReturn(List.of(
+            row, candidate(202L, 12L, 1002L, 50)));
+        assertThatThrownBy(() -> service.create(List.of(11L, 12L), key, 7L, "operator"))
+            .isInstanceOf(BizException.class)
+            .hasMessageContaining("订单“FO-11”", "入仓码“IN-1001”", reason)
+            .hasMessageNotContaining("订单 11")
+            .hasMessageNotContaining("groupId")
+            .hasMessageNotContaining("inboundId");
+    }
+
     private static GroupRow group(long id, String status, Long planId, int version) {
         GroupRow value = new GroupRow();
         value.setId(id); value.setGroupNo("CLG-" + id); value.setGroupStatus(status);
diff --git a/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupSqlContractTest.java b/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupSqlContractTest.java
index 2ccb20f25..4404c8d1b 100644
--- a/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupSqlContractTest.java
+++ b/firstleg/src/test/java/com/baiyue/firstleg/loading/coload/ColoadGroupSqlContractTest.java
@@ -42,6 +42,8 @@ class ColoadGroupSqlContractTest {
         String sql = String.join(" ", method.getAnnotation(Select.class).value());
         assertThat(sql)
             .contains("FROM fl_inbound_order o")
+            .contains("o.order_no orderNo", "o.inbound_code inboundCode")
+            .contains("o.warehouse_name warehouseName", "o.channel_name channelName")
             .contains("FROM fl_loading_plan_item item")
             .contains("item.deleted=0")
             .contains("member.active_flag=1")