diff --git a/deploy/sql/README.md b/deploy/sql/README.md
index 7a69bb335..be1ea2931 100644
--- a/deploy/sql/README.md
+++ b/deploy/sql/README.md
@@ -1,6 +1,6 @@
 # 单测试环境数据库空库初始化
 
-内部拼车需求池的当前结构在 Lastleg 源基线和海外统一空库基线同步维护，独立五项权限在 IAM 源种子和国内统一基线维护。已存在基础表的指定环境结构补齐使用 `migrations/overseas/baiyue_lastleg/V10__fleet_capacity_pool.sql` 与 `migrations/cn/baiyue_iam/V4__fleet_capacity_offer_permissions.sql`；执行前确认三张新表、六个新增字段均未存在，并单独核对目标环境。它们不回填、删除或重置业务数据，不能重放整个空库基线。候选文件存在不表示已经执行。
+内部拼车需求池的当前结构在 Lastleg 源基线和海外统一空库基线同步维护，独立五项权限在 IAM 源种子和国内统一基线维护。已存在基础表的指定环境结构补齐使用 `migrations/overseas/baiyue_lastleg/V10__fleet_capacity_pool.sql` 与 `migrations/cn/baiyue_iam/V4__fleet_capacity_offer_permissions.sql`；执行前确认三张新表、六个新增字段均未存在，并单独核对目标环境。随后 `V11__align_capacity_pool_collation.sql` 将预订与商业桥的客户关联字段显式统一为 `utf8mb4_unicode_ci`，与原订单域一致，避免依赖MySQL实例默认排序规则导致JOIN失败。它们不回填、删除或重置业务数据，不能重放整个空库基线。候选文件存在不表示已经执行。
 
 ## 唯一入口与区域边界
 
diff --git a/deploy/sql/migrations/overseas/baiyue_lastleg/V11__align_capacity_pool_collation.sql b/deploy/sql/migrations/overseas/baiyue_lastleg/V11__align_capacity_pool_collation.sql
new file mode 100644
index 000000000..477eb0c40
--- /dev/null
+++ b/deploy/sql/migrations/overseas/baiyue_lastleg/V11__align_capacity_pool_collation.sql
@@ -0,0 +1,7 @@
+-- Region: OVERSEAS
+-- Schema: baiyue_lastleg
+-- Purpose: 拼车履约客户关联字段与现有订单域排序规则一致
+-- Preconditions: 外接预订和商业履约桥已存在，客户字段为VARCHAR(128)且非空
+-- Postconditions: 两个客户关联字段使用utf8mb4_unicode_ci；不修改客户标识或业务状态
+ALTER TABLE ll_fleet_external_booking MODIFY COLUMN customer_id VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '委托客户及付款归属';
+ALTER TABLE ll_fleet_pool_order_link MODIFY COLUMN customer_id VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '商业客户隔离范围';
diff --git a/deploy/sql/海外区域统一增量-MySQL8.sql b/deploy/sql/海外区域统一增量-MySQL8.sql
index fbf6a80e2..68869770b 100644
--- a/deploy/sql/海外区域统一增量-MySQL8.sql
+++ b/deploy/sql/海外区域统一增量-MySQL8.sql
@@ -2810,7 +2810,7 @@ CREATE TABLE ll_fleet_external_booking (
   booking_no VARCHAR(32) NOT NULL COMMENT '外接预订业务编号',
   trip_id BIGINT NOT NULL COMMENT '所属车次',
   trip_no VARCHAR(32) NOT NULL COMMENT '车次业务编号',
-  customer_id VARCHAR(128) NOT NULL COMMENT '委托客户及付款归属',
+  customer_id VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '委托客户及付款归属',
   customer_code VARCHAR(64) NOT NULL COMMENT '客户编号快照',
   customer_name VARCHAR(255) NOT NULL COMMENT '客户名称快照',
   status VARCHAR(16) NOT NULL COMMENT 'DRAFT询价/CONFIRMED占位/RECEIVED确认实收/BOUND关联发运/CANCELLED取消',
@@ -2863,7 +2863,7 @@ CREATE TABLE ll_fleet_pool_order_link (
   id BIGINT NOT NULL COMMENT '内部主键',
   booking_id BIGINT NOT NULL COMMENT '唯一外接预订',
   booking_no VARCHAR(64) NOT NULL COMMENT '预订业务编号',
-  customer_id VARCHAR(128) NOT NULL COMMENT '商业客户隔离范围',
+  customer_id VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '商业客户隔离范围',
   business_type VARCHAR(32) NOT NULL COMMENT '本土散板或本土卡车商业类型',
   business_order_id BIGINT NOT NULL COMMENT '对应商业订单内部关联',
   business_order_no VARCHAR(64) NOT NULL COMMENT '本土商业订单业务编号',
diff --git a/lastleg-service/src/main/resources/db/lastleg.sql b/lastleg-service/src/main/resources/db/lastleg.sql
index adfba4afa..e4ce34539 100644
--- a/lastleg-service/src/main/resources/db/lastleg.sql
+++ b/lastleg-service/src/main/resources/db/lastleg.sql
@@ -1175,7 +1175,7 @@ CREATE TABLE ll_fleet_external_booking (
   booking_no VARCHAR(32) NOT NULL COMMENT '外接预订业务编号',
   trip_id BIGINT NOT NULL COMMENT '所属车次',
   trip_no VARCHAR(32) NOT NULL COMMENT '车次业务编号',
-  customer_id VARCHAR(128) NOT NULL COMMENT '委托客户及付款归属',
+  customer_id VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '委托客户及付款归属',
   customer_code VARCHAR(64) NOT NULL COMMENT '客户编号快照',
   customer_name VARCHAR(255) NOT NULL COMMENT '客户名称快照',
   status VARCHAR(16) NOT NULL COMMENT 'DRAFT询价/CONFIRMED占位/RECEIVED确认实收/BOUND关联发运/CANCELLED取消',
@@ -1228,7 +1228,7 @@ CREATE TABLE ll_fleet_pool_order_link (
   id BIGINT NOT NULL COMMENT '内部主键',
   booking_id BIGINT NOT NULL COMMENT '唯一外接预订',
   booking_no VARCHAR(64) NOT NULL COMMENT '预订业务编号',
-  customer_id VARCHAR(128) NOT NULL COMMENT '商业客户隔离范围',
+  customer_id VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '商业客户隔离范围',
   business_type VARCHAR(32) NOT NULL COMMENT '本土散板或本土卡车商业类型',
   business_order_id BIGINT NOT NULL COMMENT '对应商业订单内部关联',
   business_order_no VARCHAR(64) NOT NULL COMMENT '本土商业订单业务编号',
diff --git a/scripts/admin-test-env-modules/fleet-capacity-pool-schema-contract.test.mjs b/scripts/admin-test-env-modules/fleet-capacity-pool-schema-contract.test.mjs
index 8e392734b..e6cc9080e 100644
--- a/scripts/admin-test-env-modules/fleet-capacity-pool-schema-contract.test.mjs
+++ b/scripts/admin-test-env-modules/fleet-capacity-pool-schema-contract.test.mjs
@@ -46,6 +46,15 @@ test('module and unified fresh baselines contain the exact same new table defini
   assert.match(sql, /ADD CONSTRAINT fk_fleet_booking_offer/i)
 })
 
+test('customer identity joins use the same explicit collation as existing fulfillment orders', () => {
+  for (const name of ['ll_fleet_external_booking', 'll_fleet_pool_order_link']) {
+    assert.match(table(overseas, 'baiyue_lastleg', name), /customer_id VARCHAR\(128\) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL/i)
+  }
+  const sql = read('deploy/sql/migrations/overseas/baiyue_lastleg/V11__align_capacity_pool_collation.sql')
+  assert.equal((sql.match(/MODIFY COLUMN customer_id/g) || []).length, 2)
+  assert.doesNotMatch(sql.replace(/^--.*$/gm, ''), /\b(?:DROP|TRUNCATE|DELETE|UPDATE|REPLACE)\b/i)
+})
+
 test('pool permissions are independent of trip details and default only to the platform administrator', () => {
   const permissions = seedRows(cn, 'iam_permission').filter(row => String(row.permission_code).startsWith('platform:fleet:capacity-offer:'))
   assert.equal(permissions.length, 5)