diff --git a/internal/logic/public/subscribe/promo.go b/internal/logic/public/subscribe/promo.go
index ae4d711..1c0865c 100644
--- a/internal/logic/public/subscribe/promo.go
+++ b/internal/logic/public/subscribe/promo.go
@@ -90,7 +90,16 @@ func loadSubscribePromoMap(ctx context.Context, svcCtx *svc.ServiceContext, subs
 
 func querySubscribePromoCandidates(ctx context.Context, svcCtx *svc.ServiceContext, subscribeIDs []int64, loggedIn bool) ([]subscribePromoCandidate, error) {
 	var candidates []subscribePromoCandidate
-	query := svcCtx.DB.WithContext(ctx).
+	err := subscribePromoCandidatesQuery(ctx, svcCtx.DB, subscribeIDs, loggedIn).
+		Scan(&candidates).Error
+	if err != nil {
+		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "query subscribe promo candidates failed: %v", err)
+	}
+	return candidates, nil
+}
+
+func subscribePromoCandidatesQuery(ctx context.Context, db *gorm.DB, subscribeIDs []int64, loggedIn bool) *gorm.DB {
+	query := db.WithContext(ctx).
 		Table("subscribe_promo AS sp").
 		Select("sp.subscribe_id, sp.quantity, sp.promo_price, pr.name AS rule_name, pr.type AS rule_type, pr.params, pr.start_time, pr.end_time").
 		Joins("JOIN promo_rule AS pr ON pr.id = sp.promo_rule_id AND pr.deleted_at IS NULL").
@@ -98,16 +107,11 @@ func querySubscribePromoCandidates(ctx context.Context, svcCtx *svc.ServiceConte
 	if !loggedIn {
 		query = query.Where("pr.type = ?", promoRuleTypeCampaign)
 	}
-	err := query.
+	return query.
 		Order("sp.subscribe_id ASC").
 		Order("sp.quantity ASC").
 		Order("pr.priority DESC").
-		Order("pr.id ASC").
-		Scan(&candidates).Error
-	if err != nil {
-		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "query subscribe promo candidates failed: %v", err)
-	}
-	return candidates, nil
+		Order("pr.id ASC")
 }
 
 func (c subscribePromoCandidate) isActive(now time.Time) bool {
diff --git a/internal/logic/public/subscribe/promo_test.go b/internal/logic/public/subscribe/promo_test.go
index 1f432b9..4a20e0c 100644
--- a/internal/logic/public/subscribe/promo_test.go
+++ b/internal/logic/public/subscribe/promo_test.go
@@ -1,11 +1,13 @@
 package subscribe
 
 import (
+	"context"
 	"strings"
 	"testing"
 	"time"
 
 	"github.com/perfect-panel/server/internal/model/user"
+	"github.com/perfect-panel/server/internal/types"
 	"gorm.io/driver/mysql"
 	"gorm.io/gorm"
 )
@@ -107,3 +109,52 @@ func TestLastSubscribeExpireAtPrioritizesPermanentSubscription(t *testing.T) {
 		t.Fatalf("permanent subscription order var = %v, want %v; vars=%v", got, want, tx.Statement.Vars)
 	}
 }
+
+func TestQuerySubscribePromoCandidatesIncludesQuantity(t *testing.T) {
+	db, err := gorm.Open(mysql.New(mysql.Config{
+		DSN:                       "gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True&loc=Local",
+		SkipInitializeWithVersion: true,
+	}), &gorm.Config{DryRun: true, DisableAutomaticPing: true})
+	if err != nil {
+		t.Fatalf("open dry-run db: %v", err)
+	}
+
+	var candidates []subscribePromoCandidate
+	tx := subscribePromoCandidatesQuery(context.Background(), db, []int64{11, 12}, true).Scan(&candidates)
+	stmt := tx.Statement
+	sql := stmt.SQL.String()
+	if !strings.Contains(sql, "sp.subscribe_id, sp.quantity, sp.promo_price") {
+		t.Fatalf("SQL missing quantity select: %s", sql)
+	}
+	if !strings.Contains(sql, "ORDER BY sp.subscribe_id ASC,sp.quantity ASC,pr.priority DESC,pr.id ASC") {
+		t.Fatalf("SQL missing quantity order: %s", sql)
+	}
+}
+
+func TestApplySubscribeDiscountPromosMatchesQuantity(t *testing.T) {
+	subscribe := types.Subscribe{Discount: []types.SubscribeDiscount{
+		{Quantity: 1},
+		{Quantity: 12},
+	}}
+	promos := map[int64]*types.SubscribePromo{
+		3:  {RuleName: "季度优惠", PromoPrice: 2900},
+		12: {RuleName: "年度优惠", PromoPrice: 9900},
+	}
+
+	applySubscribeDiscountPromos(&subscribe, promos)
+	if subscribe.Discount[0].Promo != nil {
+		t.Fatalf("quantity 1 promo should be nil, got %+v", subscribe.Discount[0].Promo)
+	}
+	if subscribe.Discount[1].Promo == nil {
+		t.Fatal("quantity 12 promo should match")
+	}
+	if got, want := subscribe.Discount[1].Promo.RuleName, "年度优惠"; got != want {
+		t.Fatalf("promo rule name = %q, want %q", got, want)
+	}
+
+	subscribe = types.Subscribe{Discount: []types.SubscribeDiscount{{Quantity: 6}}}
+	applySubscribeDiscountPromos(&subscribe, promos)
+	if subscribe.Discount[0].Promo != nil {
+		t.Fatalf("promo should be nil when quantity does not match, got %+v", subscribe.Discount[0].Promo)
+	}
+}
diff --git a/internal/model/promo/promo.go b/internal/model/promo/promo.go
index 053878f..5218d29 100644
--- a/internal/model/promo/promo.go
+++ b/internal/model/promo/promo.go
@@ -35,7 +35,6 @@ type SubscribePromo struct {
 	SubscribeId int64     `gorm:"type:bigint unsigned;not null;comment:Subscribe ID"`
 	Quantity    int64     `gorm:"type:bigint;not null;default:1;comment:Quantity"`
 	PromoRuleId int64     `gorm:"type:bigint unsigned;not null;comment:Promo Rule ID"`
-	Quantity    int64     `gorm:"type:bigint;not null;default:1;comment:Subscribe Quantity"`
 	PromoPrice  int64     `gorm:"type:bigint;not null;default:0;comment:Promo Price"`
 	CreatedAt   time.Time `gorm:"<-:create;comment:Create Time"`
 	UpdatedAt   time.Time `gorm:"comment:Update Time"`