diff --git a/backend/services/identity-service/src/infrastructure/external/mpc/mpc-client.service.ts b/backend/services/identity-service/src/infrastructure/external/mpc/mpc-client.service.ts
index 0c214717..bfcd2782 100644
--- a/backend/services/identity-service/src/infrastructure/external/mpc/mpc-client.service.ts
+++ b/backend/services/identity-service/src/infrastructure/external/mpc/mpc-client.service.ts
@@ -79,10 +79,10 @@ export class MpcClientService {
   }
 
   /**
-   * 生成新的会话ID
+   * 生成新的会话ID (必须是纯 UUID 格式)
    */
   generateSessionId(): string {
-    return `mpc-${randomUUID()}`;
+    return randomUUID();
   }
 
   /**
@@ -112,7 +112,7 @@ export class MpcClientService {
             sessionId: request.sessionId,
             partyId: 'server-party',
             joinToken: this.generateJoinToken(request.sessionId),
-            shareType: 'SERVER',
+            shareType: 'wallet',  // PartyShareType.WALLET
             userId: request.parties.find(p => p.partyType === 'CLIENT')?.partyId,
           },
           {