diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index 85e61de3..225f5629 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -564,7 +564,8 @@
       "Bash(go run:*)",
       "Bash(pkill:*)",
       "Bash(timeout 120 go run:*)",
-      "Bash(timeout 60 go run:*)"
+      "Bash(timeout 60 go run:*)",
+      "Bash(git commit -m \"$\\(cat <<''EOF''\nfix\\(transfer\\): pass sessionId and participants to executeSign\n\n- Add signSessionId state to store the session ID from createSignSession\n- Add ParticipantInfo interface and participants field to ShareInfo\n- Build participants list from share data for executeSign call\n- Fix \"Party not found in participants list\" error\n\n🤖 Generated with [Claude Code]\\(https://claude.com/claude-code\\)\n\nCo-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>\nEOF\n\\)\")"
     ],
     "deny": [],
     "ask": []
diff --git a/backend/mpc-system/services/service-party-app/electron/main.ts b/backend/mpc-system/services/service-party-app/electron/main.ts
index 5ea93e96..c0f9e2ce 100644
--- a/backend/mpc-system/services/service-party-app/electron/main.ts
+++ b/backend/mpc-system/services/service-party-app/electron/main.ts
@@ -564,9 +564,10 @@ async function handleKeygenComplete(result: KeygenResult) {
   try {
     // 1. 保存 share 到本地数据库
     const publicKeyHex = result.publicKey.toString('hex');
-    // 转换 participants 格式：从 { partyId, partyIndex, name } 到 { partyId, name }
+    // 转换 participants 格式：保存 partyId, partyIndex, name
     const participantsForSave = activeKeygenSession.participants.map(p => ({
       partyId: p.partyId,
+      partyIndex: p.partyIndex,
       name: p.name,
     }));
     const saved = database.saveShare({
@@ -1220,9 +1221,9 @@ function setupIpcHandlers() {
 
       // 解析 participants_json 获取参与方列表
       const participants = JSON.parse(share.participants_json || '[]');
-      const parties = participants.map((p: { partyId: string }, index: number) => ({
+      const parties = participants.map((p: { partyId: string; partyIndex?: number }, index: number) => ({
         party_id: p.partyId,
-        party_index: index,
+        party_index: p.partyIndex ?? index, // 优先使用保存的 partyIndex，否则使用数组索引
       }));
 
       const result = await accountClient?.createSignSession({
diff --git a/backend/mpc-system/services/service-party-app/src/pages/Sign.tsx b/backend/mpc-system/services/service-party-app/src/pages/Sign.tsx
index abcf5e3d..98720f35 100644
--- a/backend/mpc-system/services/service-party-app/src/pages/Sign.tsx
+++ b/backend/mpc-system/services/service-party-app/src/pages/Sign.tsx
@@ -2,25 +2,35 @@ import { useState, useEffect } from 'react';
 import { useNavigate, useParams } from 'react-router-dom';
 import styles from './Sign.module.css';
 
+interface ParticipantInfo {
+  partyId: string;
+  partyIndex?: number;
+  name?: string;
+}
+
 interface ShareItem {
   id: string;
   walletName: string;
   publicKey: string;
+  sessionId: string;
   threshold: { t: number; n: number };
   createdAt: string;
-  metadata: {
+  participants?: ParticipantInfo[];
+  metadata?: {
     participants: Array<{ partyId: string; name: string }>;
   };
 }
 
 interface SigningSession {
   sessionId: string;
+  keygenSessionId?: string;
   walletName: string;
   messageHash: string;
   threshold: { t: number; n: number };
   currentParticipants: number;
   initiator: string;
   joinToken?: string;
+  parties?: Array<{ party_id: string; party_index: number }>;
 }
 
 export default function Sign() {
@@ -117,6 +127,10 @@ export default function Sign() {
       setError('请选择要使用的钱包份额');
       return;
     }
+    if (!signingSession) {
+      setError('签名会话信息丢失');
+      return;
+    }
     setIsLoading(true);
     setError(null);
     setStep('signing');
@@ -132,36 +146,48 @@ export default function Sign() {
       }
 
       // 加入签名会话
-      const result = await window.electronAPI.grpc.joinSigningSession({
-        sessionId: signingSession!.sessionId,
+      const joinResult = await window.electronAPI.grpc.joinSigningSession({
+        sessionId: signingSession.sessionId,
         shareId: selectedShare.id,
         password: password,
-        joinToken: signingSession!.joinToken,
+        joinToken: signingSession.joinToken,
       });
 
-      if (result.success) {
-        // 订阅签名进度
-        window.electronAPI.grpc.subscribeSigningProgress(
-          signingSession!.sessionId,
-          (event) => {
-            if (event.type === 'progress') {
-              setProgress({ current: event.current || 0, total: event.total || 0 });
-            } else if (event.type === 'completed') {
-              setSignature(event.signature || '');
-              setStep('completed');
-              setIsLoading(false);
-            } else if (event.type === 'failed') {
-              setError(event.error || '签名失败');
-              setStep('failed');
-              setIsLoading(false);
-            }
-          }
-        );
-      } else {
-        setError(result.error || '加入签名会话失败');
+      if (!joinResult.success) {
+        setError(joinResult.error || '加入签名会话失败');
         setStep('join');
         setIsLoading(false);
+        return;
       }
+
+      // 构建 participants 列表
+      // 优先使用签名会话返回的 parties（包含正确的 party_index）
+      const participants = signingSession.parties?.map(p => ({
+        partyId: p.party_id,
+        partyIndex: p.party_index,
+      })) || (selectedShare.participants || []).map((p, index) => ({
+        partyId: p.partyId,
+        partyIndex: p.partyIndex ?? index,
+      }));
+
+      // 执行 TSS 签名
+      const signResult = await window.electronAPI.grpc.executeSign({
+        sessionId: signingSession.sessionId,
+        shareId: selectedShare.id,
+        password: password,
+        messageHash: signingSession.messageHash,
+        participants,
+        threshold: signingSession.threshold,
+      });
+
+      if (signResult.success && signResult.signature) {
+        setSignature(signResult.signature);
+        setStep('completed');
+      } else {
+        setError(signResult.error || '签名失败');
+        setStep('failed');
+      }
+      setIsLoading(false);
     } catch (err) {
       setError('签名过程出错: ' + (err as Error).message);
       setStep('failed');
diff --git a/backend/mpc-system/services/service-party-app/src/pages/Transfer.tsx b/backend/mpc-system/services/service-party-app/src/pages/Transfer.tsx
index dbc2a164..3c8568fd 100644
--- a/backend/mpc-system/services/service-party-app/src/pages/Transfer.tsx
+++ b/backend/mpc-system/services/service-party-app/src/pages/Transfer.tsx
@@ -18,6 +18,7 @@ import { deriveEvmAddress, formatAddress } from '../utils/address';
 
 interface ParticipantInfo {
   partyId: string;
+  partyIndex?: number;
   name?: string;
 }
 
@@ -233,7 +234,7 @@ export default function Transfer() {
       // 构建 participants 列表
       const participants = (share.participants || []).map((p, index) => ({
         partyId: p.partyId,
-        partyIndex: index,
+        partyIndex: p.partyIndex ?? index, // 优先使用保存的 partyIndex
       }));
 
       // 执行 TSS 签名