diff --git a/src/modules/first-leg/components/CustomsDocumentsDialog.test.mjs b/src/modules/first-leg/components/CustomsDocumentsDialog.test.mjs
new file mode 100644
index 0000000..02d19ab
--- /dev/null
+++ b/src/modules/first-leg/components/CustomsDocumentsDialog.test.mjs
@@ -0,0 +1,71 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { readFileSync } from 'node:fs'
+import ts from 'typescript'
+import * as vue from 'vue'
+
+function deferred() { let resolve, reject; const promise = new Promise((yes, no) => { resolve = yes; reject = no }); return { promise, resolve, reject } }
+function harness(t) {
+  const source = readFileSync(new URL('./CustomsDocumentsDialog.vue', import.meta.url), 'utf8').match(/<script setup lang="ts">([\s\S]*?)<\/script>/)[1]
+  const code = ts.transpileModule(source + '\nexport { loadDetail, detail, clearanceResults, loading, errorMessage, selectedInboundIds }', { compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES2022 } }).outputText
+  const props = vue.reactive({ modelValue: false, orderId: 'A', canEdit: true }), requests = [], clearances = [], updates = [], view = {}
+  const unmounts = []
+  const dependencies = { vue: { ...vue, onBeforeUnmount: fn => unmounts.push(fn) }, 'element-plus': { ElMessage: {} }, '@/modules/first-leg/api/customs': {
+    getMerchantCustomsForOrder: id => { const pending = deferred(); requests.push({ id, ...pending }); return pending.promise },
+    getMerchantClearanceResults: id => { const pending = deferred(); clearances.push({ id, ...pending }); return pending.promise },
+    merchantCustomsErrorMessage: error => error.message,
+  } }
+  const scope = vue.effectScope()
+  scope.run(() => new Function('require', 'exports', 'defineProps', 'defineEmits', code)(id => {
+    assert.ok(id in dependencies, id); return dependencies[id]
+  }, view, () => props, () => (...args) => updates.push(args)))
+  t.after(() => scope.stop())
+  return { props, requests, clearances, updates, view, unmount: () => unmounts.forEach(fn => fn()) }
+}
+const detail = id => ({ loadingPlanId: id, inbounds: [{ orderId: id, inboundId: `IN-${id}`, taxMode: 'TAX_REFUND' }] })
+const tick = async () => { await Promise.resolve(); await vue.nextTick(); await Promise.resolve() }
+
+test('switching orders while open starts the new request and ignores stale detail', async t => {
+  const h = harness(t); h.props.modelValue = true; await tick()
+  h.props.orderId = 'B'; await tick()
+  assert.deepEqual(h.requests.map(r => r.id), ['A', 'B'])
+  h.requests[1].resolve(detail('B')); await tick(); h.clearances[0].resolve([]); await tick()
+  h.requests[0].resolve(detail('A')); await tick()
+  assert.equal(h.view.detail.value.loadingPlanId, 'B')
+  assert.deepEqual(h.view.selectedInboundIds.value, ['IN-B'])
+  assert.deepEqual(h.clearances.map(r => r.id), ['B'])
+  assert.equal(h.updates.length, 1)
+})
+
+test('closing before detail response prevents stale data and events', async t => {
+  const h = harness(t); h.props.modelValue = true; await tick()
+  h.props.modelValue = false; await tick()
+  h.requests[0].resolve(detail('A')); await tick()
+  assert.equal(h.view.detail.value, null); assert.equal(h.view.loading.value, false)
+  assert.equal(h.clearances.length, 0); assert.equal(h.updates.length, 0)
+})
+
+test('closing and reopening ignores the previous clearance response', async t => {
+  const h = harness(t); h.props.modelValue = true; await tick()
+  h.requests[0].resolve(detail('A')); await tick()
+  h.props.modelValue = false; await tick(); h.props.orderId = 'B'; h.props.modelValue = true; await tick()
+  h.requests[1].resolve(detail('B')); await tick()
+  h.clearances[1].resolve([{ kind: 'B' }]); await tick()
+  h.clearances[0].resolve([{ kind: 'A' }]); await tick()
+  assert.deepEqual(h.view.clearanceResults.value, [{ kind: 'B' }])
+  assert.equal(h.view.detail.value.loadingPlanId, 'B'); assert.equal(h.updates.length, 1)
+})
+
+test('stale detail failure cannot clear the next request loading or show an error', async t => {
+  const h = harness(t); h.props.modelValue = true; await tick()
+  h.props.orderId = 'B'; await tick(); h.requests[0].reject(new Error('old failure')); await tick()
+  assert.equal(h.view.loading.value, true); assert.equal(h.view.errorMessage.value, '')
+  h.requests[1].resolve(detail('B')); await tick(); h.clearances[0].resolve([]); await tick()
+  assert.equal(h.view.loading.value, false); assert.equal(h.view.detail.value.loadingPlanId, 'B')
+})
+
+test('unmount invalidates pending detail requests', async t => {
+  const h = harness(t); h.props.modelValue = true; await tick(); h.unmount()
+  h.requests[0].resolve(detail('A')); await tick()
+  assert.equal(h.clearances.length, 0); assert.equal(h.updates.length, 0); assert.equal(h.view.detail.value, null)
+})
diff --git a/src/modules/first-leg/components/CustomsDocumentsDialog.vue b/src/modules/first-leg/components/CustomsDocumentsDialog.vue
index 5b05e43..79f9c1f 100644
--- a/src/modules/first-leg/components/CustomsDocumentsDialog.vue
+++ b/src/modules/first-leg/components/CustomsDocumentsDialog.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { computed, nextTick, ref, watch } from 'vue'
+import { computed, nextTick, onBeforeUnmount, ref, watch } from 'vue'
 import { ElMessage, ElMessageBox } from 'element-plus'
 import { Download, FileText, LockKeyhole, Pencil, Trash2, Upload } from '@lucide/vue'
 import {
@@ -46,6 +46,8 @@ const replaceInput = ref<HTMLInputElement>()
 const mutating = ref(false)
 const downloadingKey = ref('')
 const clearanceResults = ref<MerchantClearanceResult[]>([])
+let detailRequest = 0
+onBeforeUnmount(() => { detailRequest += 1 })
 
 const taxRefundInbounds = computed(() => detail.value?.inbounds.filter((item) => item.taxMode === 'TAX_REFUND') ?? [])
 const locked = computed(() => Boolean(detail.value?.startedAt) || detail.value?.status === 'DECLARING' || detail.value?.status === 'COMPLETED')
@@ -67,29 +69,46 @@ function initializeSelection(value: MerchantCustomsContainer) {
 }
 
 async function loadDetail() {
-  if (!props.orderId) return
+  if (!props.modelValue || !props.orderId) return
+  const request = ++detailRequest
+  const orderId = props.orderId
+  const isCurrent = () => request === detailRequest && props.modelValue && props.orderId === orderId
   loading.value = true
   errorMessage.value = ''
   try {
-    const result = await getMerchantCustomsForOrder(props.orderId)
+    const result = await getMerchantCustomsForOrder(orderId)
+    if (!isCurrent()) return
     detail.value = result
     initializeSelection(result)
-    try { clearanceResults.value = await getMerchantClearanceResults(props.orderId) } catch { clearanceResults.value = [] }
+    let results: MerchantClearanceResult[] = []
+    try { results = await getMerchantClearanceResults(orderId) } catch { /* Detail remains available for a failed result query. */ }
+    if (!isCurrent()) return
+    clearanceResults.value = results
     emit('updated', result)
   } catch (error) {
+    if (!isCurrent()) return
     detail.value = null
     errorMessage.value = merchantCustomsErrorMessage(error, '退税报关资料加载失败')
   } finally {
-    loading.value = false
+    if (isCurrent()) loading.value = false
   }
 }
 
-watch(() => props.modelValue, (open) => {
+watch(() => [props.modelValue, props.orderId] as const, ([open]) => {
+  detailRequest += 1
+  detail.value = null
+  clearanceResults.value = []
+  selectedInboundIds.value = []
+  editingDocument.value = null
+  replacingDocument.value = null
+  errorMessage.value = ''
+  loading.value = false
   if (!open) return
-  detail.value = props.initialDetail ?? null
+  const initial = props.initialDetail
+  detail.value = initial?.inbounds.some((item) => item.orderId === props.orderId) ? initial : null
   if (detail.value) initializeSelection(detail.value)
   void loadDetail()
-})
+}, { immediate: true })
 
 function close() {
   emit('update:modelValue', false)