diff --git a/apps/backend/src/services/fulfillment/product-resolution-service.test.ts b/apps/backend/src/services/fulfillment/product-resolution-service.test.ts
index c00f337f..65727905 100644
--- a/apps/backend/src/services/fulfillment/product-resolution-service.test.ts
+++ b/apps/backend/src/services/fulfillment/product-resolution-service.test.ts
@@ -3,6 +3,7 @@ import test from 'node:test'
 
 import {
   matchAffiliateDashSku,
+  matchAffiliateDashSkuPassthrough,
   normalizeAffiliateDashMappingKey,
 } from './product-resolution-service.js'
 
@@ -32,3 +33,21 @@ test('normalizeAffiliateDashMappingKey NFKC + 去空白 + 小写', () => {
   assert.equal(normalizeAffiliateDashMappingKey(' 幸运币９０个　'), '幸运币90个')
   assert.equal(normalizeAffiliateDashMappingKey('M416-仓鼠灰灰'), 'm416-仓鼠灰灰')
 })
+
+test('matchAffiliateDashSkuPassthrough sku 一致时命中', () => {
+  const skus = new Set(['suit_alan_walker', 'lucky_coin_x90'])
+  assert.equal(matchAffiliateDashSkuPassthrough('suit_alan_walker', skus), true)
+  assert.equal(matchAffiliateDashSkuPassthrough('lucky_coin_x90', skus), true)
+})
+
+test('matchAffiliateDashSkuPassthrough 不在商品列表时未命中', () => {
+  const skus = new Set(['suit_alan_walker'])
+  assert.equal(matchAffiliateDashSkuPassthrough('not_a_real_sku', skus), false)
+  assert.equal(matchAffiliateDashSkuPassthrough('', skus), false)
+  assert.equal(matchAffiliateDashSkuPassthrough('suit_alan_walker', null), false)
+  assert.equal(matchAffiliateDashSkuPassthrough('suit_alan_walker', undefined), false)
+})
+
+test('matchAffiliateDashSkuPassthrough 空集合未命中', () => {
+  assert.equal(matchAffiliateDashSkuPassthrough('suit_alan_walker', new Set()), false)
+})
diff --git a/apps/backend/src/services/fulfillment/product-resolution-service.ts b/apps/backend/src/services/fulfillment/product-resolution-service.ts
index 85ab0fe1..b9e66f30 100644
--- a/apps/backend/src/services/fulfillment/product-resolution-service.ts
+++ b/apps/backend/src/services/fulfillment/product-resolution-service.ts
@@ -12,6 +12,7 @@ import {
   type FulfillmentRouteResult,
 } from './routing-config-service.js'
 import { getAffiliateDashConfig } from '../platforms/affiliate-dash/config.js'
+import { listAllAffiliateDashProducts } from '../platforms/affiliate-dash/product-service.js'
 import type { AffiliateDashSkuMapping } from '../../types/runtime-config.js'
 import { FULFILLMENT_EXECUTOR_KEYS } from './executors/types.js'
 
@@ -42,7 +43,7 @@ export type AffiliateDashSkuMatch = {
   sku: string
   productNo: string
   skuName: string
-  matchMode: 'affiliate_dash_sku_mapping'
+  matchMode: 'affiliate_dash_sku_mapping' | 'affiliate_dash_sku_passthrough'
 }
 
 type FulfillmentItemCandidate = {
@@ -234,7 +235,7 @@ async function resolveConfiguredItemCandidate({
   if (isOpen91KuaishouOrder(provider, platform)) {
     const cloudtentaclesNameMatch = await resolveCloudtentaclesSkuByProductName(externalSkuName)
     const kuaishouFeifeiMatch = resolveKuaishouFeifeiProductByName(externalSkuName)
-    const affiliateDashMatch = resolveAffiliateDashSkuByProductNo(item)
+    const affiliateDashMatch = await resolveAffiliateDashSkuByProductNo(item)
     // 指定匹配（显式映射）命中时优先走 affiliate_dash（可配置关闭，默认开）
     const affiliateDashConfig = getAffiliateDashConfig()
     const preferredExecutorKey =
@@ -310,7 +311,9 @@ async function resolveConfiguredItemCandidate({
   }
 }
 
-function resolveAffiliateDashSkuByProductNo(item: FulfillmentItem): AffiliateDashSkuMatch | null {
+async function resolveAffiliateDashSkuByProductNo(
+  item: FulfillmentItem,
+): Promise<AffiliateDashSkuMatch | null> {
   const config = getAffiliateDashConfig()
   if (config.enabled === false || !config.baseUrl) {
     return null
@@ -322,16 +325,62 @@ function resolveAffiliateDashSkuByProductNo(item: FulfillmentItem): AffiliateDas
     item.externalSkuCode,
     item.externalItemId,
   ])
-  const sku = productNo ? matchAffiliateDashSku(config.skuMapping, String(productNo)) : ''
-  if (!productNo || !sku) {
+  if (!productNo) {
     return null
   }
 
-  return {
-    sku,
-    productNo: String(productNo),
-    skuName: String(item.externalSkuName || '').trim(),
-    matchMode: 'affiliate_dash_sku_mapping',
+  // ① 指定映射（运营显式配置）
+  const mappedSku = matchAffiliateDashSku(config.skuMapping, String(productNo))
+  if (mappedSku) {
+    return {
+      sku: mappedSku,
+      productNo: String(productNo),
+      skuName: String(item.externalSkuName || '').trim(),
+      matchMode: 'affiliate_dash_sku_mapping',
+    }
+  }
+
+  // ② 透传：91 商品编码 == affiliate_dash 商品 sku 时直接命中（需商品列表校验，缓存 5 分钟）
+  const rawProductNo = String(productNo).trim()
+  const skuSet = await getAffiliateDashSkuSet()
+  if (matchAffiliateDashSkuPassthrough(rawProductNo, skuSet)) {
+    return {
+      sku: rawProductNo,
+      productNo: rawProductNo,
+      skuName: String(item.externalSkuName || '').trim(),
+      matchMode: 'affiliate_dash_sku_passthrough',
+    }
+  }
+
+  return null
+}
+
+/** 透传判定：productNo 与 affiliate_dash 商品 sku 完全一致。 */
+export function matchAffiliateDashSkuPassthrough(
+  productNo: string,
+  availableSkus: ReadonlySet<string> | null | undefined,
+): boolean {
+  const raw = String(productNo || '').trim()
+  return Boolean(raw && availableSkus?.has(raw))
+}
+
+const AFFILIATE_DASH_SKU_CACHE_TTL_MS = 5 * 60 * 1000
+let affiliateDashSkuCache: { skus: Set<string>; fetchedAt: number } | null = null
+
+async function getAffiliateDashSkuSet(): Promise<Set<string>> {
+  const now = Date.now()
+  if (affiliateDashSkuCache && now - affiliateDashSkuCache.fetchedAt < AFFILIATE_DASH_SKU_CACHE_TTL_MS) {
+    return affiliateDashSkuCache.skus
+  }
+
+  try {
+    const result = await listAllAffiliateDashProducts()
+    const skus = new Set<string>(result.list.map((product) => String(product.sku || '').trim()).filter(Boolean))
+    affiliateDashSkuCache = { skus, fetchedAt: now }
+    return skus
+  } catch {
+    // 拉取失败：返回上次缓存（即使过期）或空集合，匹配 miss 走其他通道，不阻塞下单
+    return affiliateDashSkuCache?.skus || new Set<string>()
   }
 }
 
diff --git a/docs/ affiliate_dash_发货平台/affiliate-dash对接.md b/docs/ affiliate_dash_发货平台/affiliate-dash对接.md
index bf926e58..876ee676 100644
--- a/docs/ affiliate_dash_发货平台/affiliate-dash对接.md	
+++ b/docs/ affiliate_dash_发货平台/affiliate-dash对接.md	
@@ -688,3 +688,27 @@ order_site 处理要求：
 | 神秘新商品（未映射） | （无）回退 | — |
 
 **验证**：typecheck 通过；后端全量 221 测试通过（新增 9 个）。
+
+---
+
+## 23. 透传优化：91 编码 == affiliate_dash sku 自动命中（v2.8 · 已完成）
+
+**需求**：91 商品编码可直接设置为英文（= affiliate_dash sku，如 `suit_alan_walker`），映射表未命中时**自动透传**，无需在 order_site 维护映射表。
+
+### 23.1 匹配层级（`resolveAffiliateDashSkuByProductNo`，改为 async）
+
+1. **① 指定映射**（`matchAffiliateDashSku`）：skuMapping 精确/归一命中 → `matchMode='affiliate_dash_sku_mapping'`
+2. **② 透传**（`matchAffiliateDashSkuPassthrough`）：映射未命中时，productNo 与 affiliate_dash 商品 sku 完全一致 → `matchMode='affiliate_dash_sku_passthrough'`
+3. 两层任一命中都触发「指定匹配最高优先」（`preferredExecutorKey=affiliate_dash`），规则/全局优先级不抢占
+
+**商品列表缓存**：`getAffiliateDashSkuSet()` 内存缓存 5 分钟（`listAllAffiliateDashProducts` 拉全量 33 个 sku）；拉取失败返回上次缓存或空集合——匹配 miss 走其他通道，**不阻塞下单**。
+
+### 23.2 行为验证（线上商品列表）
+
+| 输入（91 编码） | executor | sku | matchMode |
+| --- | --- | --- | --- |
+| `suit_alan_walker`（真实商品） | affiliate_dash | suit_alan_walker | affiliate_dash_sku_passthrough |
+| `suit_cloud_bear`（真实商品） | affiliate_dash | suit_cloud_bear | affiliate_dash_sku_passthrough |
+| `not_a_real_sku` | （无）回退 | — | — |
+
+**验证**：typecheck 通过；后端全量 224 测试通过（透传纯函数测试 +3）。