diff --git a/docs/SHOP_DEALER_REFEREE_BINDING.md b/docs/SHOP_DEALER_REFEREE_BINDING.md
new file mode 100644
index 0000000..583bb67
--- /dev/null
+++ b/docs/SHOP_DEALER_REFEREE_BINDING.md
@@ -0,0 +1,26 @@
+# ShopDealerReferee 绑定接口规则与索引建议
+
+接口：`POST /api/shop/shop-dealer-referee`
+
+## 业务规则(后端)
+
+- 邀请人(dealerId)必须存在且有效：以 `shop_dealer_user` 记录存在且 `is_delete=0` 为准
+- 当前用户(userId)仅从 token 获取；若 body.userId 存在且与 token 不一致则拒绝
+- 禁止自己绑定自己：`dealerId == userId`
+- 仅首次绑定生效：若已存在(同一 tenant、同一 user、`level=1`)则直接返回成功(幂等，不改绑)
+- 记录溯源字段：`source`、`scene`
+
+## 并发幂等(数据库建议)
+
+建议在 `shop_dealer_referee` 增加溯源字段，并加唯一索引保证并发下不重复写入：
+
+```sql
+ALTER TABLE shop_dealer_referee
+  ADD COLUMN source VARCHAR(32) NULL COMMENT '来源(如 goods_share)',
+  ADD COLUMN scene  VARCHAR(255) NULL COMMENT '场景参数(溯源统计)';
+
+-- 约束：同一 tenant 下，一个用户每个 level 只能有一条推荐关系
+ALTER TABLE shop_dealer_referee
+  ADD UNIQUE KEY uk_shop_dealer_referee_tenant_user_level (tenant_id, user_id, level);
+```
+
diff --git a/src/main/java/com/gxwebsoft/credit/controller/CreditJudgmentDebtorController.java b/src/main/java/com/gxwebsoft/credit/controller/CreditJudgmentDebtorController.java
index e01569e..4f361a3 100644
--- a/src/main/java/com/gxwebsoft/credit/controller/CreditJudgmentDebtorController.java
+++ b/src/main/java/com/gxwebsoft/credit/controller/CreditJudgmentDebtorController.java
@@ -151,7 +151,7 @@ public class CreditJudgmentDebtorController extends BaseController {
     /**
      * 根据企业名称匹配企业并更新 companyId（匹配 CreditCompany.name / CreditCompany.matchName）
      *
-     * <p>默认仅更新 companyId 为空的记录；如需覆盖更新，传 onlyNull=false。</p>
+     * <p>默认仅更新 companyId=0 的记录；如需覆盖更新，传 onlyNull=false。</p>
      */
     @PreAuthorize("hasAuthority('credit:creditJudgmentDebtor:update')")
     @OperationLog
@@ -170,7 +170,7 @@ public class CreditJudgmentDebtorController extends BaseController {
             .eq(currentTenantId != null, CreditJudgmentDebtor::getTenantId, currentTenantId)
             .isNotNull(CreditJudgmentDebtor::getName);
         if (Boolean.TRUE.equals(onlyNull)) {
-            debtorQuery.isNull(CreditJudgmentDebtor::getCompanyId);
+            debtorQuery.eq(CreditJudgmentDebtor::getCompanyId, 0);
         }
         if (limit != null && limit > 0) {
             debtorQuery.last("limit " + Math.min(limit, 200000));
@@ -269,7 +269,7 @@ public class CreditJudgmentDebtorController extends BaseController {
 
                 boolean needUpdate = d.getCompanyId() == null || !companyId.equals(d.getCompanyId());
                 if (Boolean.TRUE.equals(onlyNull)) {
-                    needUpdate = d.getCompanyId() == null;
+                    needUpdate = d.getCompanyId() != null && d.getCompanyId() == 0;
                 }
                 if (!needUpdate) {
                     continue;