diff --git a/src/views/oa/erp/contractInfo/orderActivate.vue b/src/views/oa/erp/contractInfo/orderActivate.vue
index 26319c0..009fe4b 100644
--- a/src/views/oa/erp/contractInfo/orderActivate.vue
+++ b/src/views/oa/erp/contractInfo/orderActivate.vue
@@ -994,7 +994,7 @@ function buildProjectContractsPayload(row: ProjectRow, index: number): Record<st
     base.managerId = pf.managerId;
     base.chargeId = pf.chargeId;
     base.deputyId = pf.deputyId;
-    base.peopleId = Array.isArray(pf.peopleId) && pf.peopleId.length > 0 ? pf.peopleId.join(',') : pf.peopleId;
+    base.peopleId = normalizeProjectContractsPeopleId(pf.peopleId);
     base.amount = pf.amount;
   }
   return base;
@@ -1005,6 +1005,13 @@ function normalizePeopleId(value: string | string[] | number | undefined): strin
   return Array.isArray(value) ? value.join(',') : value;
 }
 
+/** 关联项目抄送：后端 ErpProjectContractsBo.peopleId 为 String，禁止提交 JSON 数组（含空数组） */
+function normalizeProjectContractsPeopleId(value: string | string[] | number | undefined): string | undefined {
+  const raw = normalizePeopleId(value);
+  if (raw === undefined || raw === null || raw === '') return undefined;
+  return String(raw);
+}
+
 /** 校验回款比例之和是否为 100% */
 function isRepaymentRateTotalValid(): boolean {
   const totalRate = planStageList.value.reduce((sum, item) => sum + toNumber(item.repaymentRate), 0);