diff --git a/SimpleAdmin.Application/Services/Onboarding/ElectronicSign/Qiyuesuo/QiyuesuoClient.cs b/SimpleAdmin.Application/Services/Onboarding/ElectronicSign/Qiyuesuo/QiyuesuoClient.cs
index 3881422..1028451 100644
--- a/SimpleAdmin.Application/Services/Onboarding/ElectronicSign/Qiyuesuo/QiyuesuoClient.cs
+++ b/SimpleAdmin.Application/Services/Onboarding/ElectronicSign/Qiyuesuo/QiyuesuoClient.cs
@@ -151,6 +151,9 @@ public class QiyuesuoClient : IQiyuesuoClient
                 contractId = input.ContractId,
                 bizId = input.BizId,
                 tenantName = input.CompanyName,
+                // 入职合同的签署位置由系统统一预设，禁止签署人自行增加位置，
+                // 避免同一份材料出现“预设签名 + 手动新增签名”的重复签名。
+                stamperRule = "MUST_FORBID",
                 locateAllStamperKeywords = false,
                 stampers = input.Stampers
             });