diff --git a/services/game-service/internal/service/game/baishun_adapter.go b/services/game-service/internal/service/game/baishun_adapter.go
index a3b4c6e1..5306f11c 100644
--- a/services/game-service/internal/service/game/baishun_adapter.go
+++ b/services/game-service/internal/service/game/baishun_adapter.go
@@ -341,6 +341,13 @@ func (s *Service) validBaishunSession(ctx context.Context, app string, token str
 	if token == "" {
 		return gamedomain.LaunchSession{}, xerr.New(xerr.Unauthorized, "token invalid")
 	}
+	// 百顺的 ss_token 直接复用 App access token；同一个登录 token 可能打开多款百顺游戏。
+	// JWT 必须优先解析，否则会先命中旧启动会话的 hash，并被旧 provider_game_id 误判为跨游戏复用。
+	if strings.Count(token, ".") == 2 {
+		if session, err := s.appSessionFromAccessToken(app, token); err == nil {
+			return session, nil
+		}
+	}
 	if session, err := s.validYomiSession(ctx, app, token); err == nil {
 		return session, nil
 	}
diff --git a/services/game-service/internal/service/game/service_test.go b/services/game-service/internal/service/game/service_test.go
index 5e5485d1..08351335 100644
--- a/services/game-service/internal/service/game/service_test.go
+++ b/services/game-service/internal/service/game/service_test.go
@@ -1001,6 +1001,54 @@ func TestHandleBaishunSSTokenUserInfoUpdateAndChangeBalance(t *testing.T) {
 	}
 }
 
+func TestHandleBaishunAccessTokenIgnoresStaleLaunchSessionGameID(t *testing.T) {
+	secret := "baishun-test-app-key"
+	userID := int64(312900923573673984)
+	token := leaderccTestAccessToken(t, "lalu", userID, "163004", 1700003600)
+	repo := &fakeRepository{
+		platform: gamedomain.Platform{
+			PlatformCode:             "baishun",
+			AdapterType:              gamedomain.AdapterBaishunV1,
+			CallbackSecretCiphertext: secret,
+			AdapterConfigJSON:        `{"app_id":7482496867,"app_channel":"bobi","uid_mode":"display_user_id"}`,
+		},
+		// 同一个 App access token 会被百顺 H5 作为 ss_token 复用；旧启动会话只说明曾经打开过别的游戏。
+		// 回调验权必须以 JWT 里的当前用户身份为准，否则 user_info 会被旧 provider_game_id 拦成 token invalid。
+		session: gamedomain.LaunchSession{
+			AppCode:         "lalu",
+			SessionID:       "old_baishun_launch_session",
+			UserID:          userID,
+			DisplayUserID:   "163004",
+			PlatformCode:    "baishun",
+			ProviderGameID:  "1006",
+			LaunchTokenHash: stableHash(token),
+			Status:          gamedomain.SessionActive,
+			ExpiresAtMS:     1700086400000,
+		},
+	}
+	wallet := &fakeWallet{balanceAfter: 1880}
+	user := &fakeUser{}
+	svc := New(Config{}, repo, wallet, user)
+	svc.now = func() time.Time { return time.UnixMilli(1700000000000) }
+
+	raw, _, err := svc.HandleCallback(context.Background(), &gamev1.CallbackRequest{
+		Meta:         &gamev1.RequestMeta{RequestId: "req-baishun-stale-session", AppCode: "lalu"},
+		PlatformCode: "baishun",
+		Operation:    "get_user_info",
+		RawBody:      baishunTestBody(t, secret, `{"app_id":7482496867,"user_id":"163004","ss_token":"`+token+`","provider_name":"bobi","client_ip":"104.28.244.150","game_id":1043,"currency_type":0}`, 1700000000),
+		RemoteAddr:   "3.1.174.194:443",
+	})
+	if err != nil {
+		t.Fatalf("HandleCallback get_user_info failed: %v", err)
+	}
+	if !strings.Contains(string(raw), `"code":0`) || strings.Contains(string(raw), "token invalid") || !strings.Contains(string(raw), `"user_id":"163004"`) {
+		t.Fatalf("baishun access token should ignore stale launch session game id: %s", raw)
+	}
+	if user.lastGet.GetUserId() != userID {
+		t.Fatalf("baishun userinfo must query JWT user, got %+v", user.lastGet)
+	}
+}
+
 func TestHandleCallbackChangeCoinUsesWalletAndOrderIdempotency(t *testing.T) {
 	repo := &fakeRepository{
 		launchable: gamedomain.LaunchableGame{CatalogItem: gamedomain.CatalogItem{GameID: "demo_rocket_001", ProviderGameID: "rocket_001"}},