diff --git a/server/games/erqiwang/class.paiju.js b/server/games/erqiwang/class.paiju.js
index 284b2ad..dba0c8b 100644
--- a/server/games/erqiwang/class.paiju.js
+++ b/server/games/erqiwang/class.paiju.js
@@ -638,6 +638,11 @@ var cls_youle_erqiwang_paiju = cls_youle_erqiwang_paiju || {
 			re1.cardtype = can.cardtype;
 			re1.cards = cards;          //实际打出的牌（甩错时为单张）
 			re1.shuaicuo = _shuaicuo;
+			//合法甩牌的分量构成：cardtype 只能表达单一牌型，甩牌（单张/对子/拖拉机自由混搭，
+			//design §5.4.3）会被压平成 1xx/2xx，客户端无从据此还原分组，故另行下发分量需求
+			if (o_paiju.playproc.shuai_demand){
+				re1.shuai = o_paiju.playproc.shuai_demand;
+			}
 			return re1;
 		}
 
diff --git a/server/games/erqiwang/mod.js b/server/games/erqiwang/mod.js
index ab51fc3..bb349d6 100644
--- a/server/games/erqiwang/mod.js
+++ b/server/games/erqiwang/mod.js
@@ -477,6 +477,11 @@ youle_erqiwang.chupai = function(pack){
 			msg.data.count = re.count;
 			msg.data.flower = re.flower;
 			msg.data.cardtype = re.cardtype;
+			//合法甩牌的分量构成（design §5.4.3），供前端按 拖拉机/对子/单张 分组展示；
+			//非甩牌（含甩错退化为单张）无此属性
+			if (re.shuai){
+				msg.data.shuai = re.shuai;
+			}
 			break;
 		case 2: //第二个出牌
 			msg.rpc = "chupai2";
diff --git a/server/games/erqiwang/test/test_rpc.js b/server/games/erqiwang/test/test_rpc.js
index 0db7345..3f8eed0 100644
--- a/server/games/erqiwang/test/test_rpc.js
+++ b/server/games/erqiwang/test/test_rpc.js
@@ -133,6 +133,51 @@ t.eq('埋牌 不查牌 闲家无liangpai', mpXian && mpXian.data.liangpai, undef
 t.eq('重连 可查牌 PushCards有seatlist', E.get_deskinfo(e.o_room, 1).PushCards.seatlist !== undefined, true);
 t.eq('重连 不查牌 PushCards无seatlist', E.get_deskinfo(en.o_room, 1).PushCards.seatlist, undefined);
 
+// ===================== §5.4 甩牌：chupai1 需下发分量构成 shuai（cardtype 表达不了甩牌）=====================
+// 主花色=♦(1)。庄家(0) 甩「主♦K对 + 主♦5单张」；两闲家手上一张主牌都没有 → 甩牌合法
+function mkShuai(extraToSeat1) {
+    const pj = {
+        idx: 1, step: 5, banker: 0, call: 65, flower: 1, callproc: [],
+        seatlist: [[[0, 0], [0, 0], [0, 0], [0, 0], [-1, -1]], [[0, 0], [0, 0], [0, 0], [0, 0], [-1, -1]], [[0, 0], [0, 0], [0, 0], [0, 0], [-1, -1]]],
+        playproc: {}, cards: make108()
+    };
+    for (let i = 0; i < 108; i++) pj.cards[i].dealowner = -1;             // 先全部清空
+    const give = (cid, s) => { pj.cards[cid].dealowner = s + 1; pj.cards[cid].playround = -1; };
+    give(id(1, 1, 13), 0); give(id(2, 1, 13), 0); give(id(1, 1, 5), 0);   // 庄家：主♦K对 + 主♦5
+    give(id(1, 3, 9), 1); give(id(1, 3, 8), 1); give(id(2, 3, 9), 1);     // 闲1：全副♥，无主牌
+    give(id(1, 2, 9), 2); give(id(1, 2, 8), 2); give(id(2, 2, 9), 2);     // 闲2：全副♣，无主牌
+    if (extraToSeat1) give(extraToSeat1, 1);                              // 需要造甩错时给闲1一张大主牌
+    pj.method = {
+        check_cards_valid: c => P.check_cards_valid(pj, c),
+        check_cards_inhand: (c, s) => P.check_cards_inhand(pj, c, s),
+        do_playcard: c => P.do_playcard(pj, c),
+        get_seat_cards: s => P.get_seat_cards(pj, s),
+        have_baofu: () => (pj.seatlist[0][4][0] == 0 || pj.seatlist[1][4][0] == 0 || pj.seatlist[2][4][0] == 0)
+    };
+    P.new_playround(pj, 1, 0);
+    return pj;
+}
+// 合法甩牌 → 带 shuai 分量
+let sh = mkShuai(null); let shc = setup("00000", sh);
+mod.chupai(pack(0, { cards: [id(1, 1, 13), id(2, 1, 13), id(1, 1, 5)] }));
+let shPk = shc.sent.filter(m => m.rpc === 'chupai1')[0];
+t.eq('甩牌 合法 下发 chupai1', !!shPk, true);
+t.eq('甩牌 打出3张', shPk && shPk.data.cards.length, 3);
+t.eq('甩牌 shuai=1对+1单张', shPk && shPk.data.shuai, { tractors: [], pairs: 1, singles: 1 });
+t.eq('甩牌 无 shuaicuo', shPk && shPk.data.shuaicuo, undefined);
+// 非甩牌（单一对子）→ 无 shuai
+sh = mkShuai(null); shc = setup("00000", sh);
+mod.chupai(pack(0, { cards: [id(1, 1, 13), id(2, 1, 13)] }));
+shPk = shc.sent.filter(m => m.rpc === 'chupai1')[0];
+t.eq('非甩牌(单一对子) 无 shuai', shPk && shPk.data.shuai, undefined);
+// 甩错（闲1 持大王，能压过主K对里的单张分量）→ 收回、只打最小一张、无 shuai
+sh = mkShuai((2 - 1) * 54 + 53); shc = setup("00000", sh);   // 第二副大王给闲1
+mod.chupai(pack(0, { cards: [id(1, 1, 13), id(2, 1, 13), id(1, 1, 5)] }));
+shPk = shc.sent.filter(m => m.rpc === 'chupai1')[0];
+t.eq('甩错 shuaicuo=1', shPk && shPk.data.shuaicuo, 1);
+t.eq('甩错 只打出最小一张(主♦5)', shPk && shPk.data.cards, [id(1, 1, 5)]);
+t.eq('甩错 无 shuai 分量', shPk && shPk.data.shuai, undefined);
+
 // ===================== 重连 PushCards.pushlist：结构恒 3 座位 + 按本局主牌花色排序 =====================
 // 造 5 轮已出牌的牌局（每轮每家 1 张），外加 seat0 在第 1 轮同时出「主5 + 副♥A」用于验证排序
 function mkPushlist() {