diff --git a/cmd/server/main.go b/cmd/server/main.go
index 68bb937..12e12d7 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -47,14 +47,6 @@ func main() {
 		log.Fatal("initialize database", zap.Error(err))
 	}
 
-	if err := preparePublicIDColumns(gormDB); err != nil {
-		log.Fatal("prepare public_id columns", zap.Error(err))
-	}
-
-	if err := backfillPublicIDs(gormDB); err != nil {
-		log.Fatal("backfill public ids", zap.Error(err))
-	}
-
 	if err := gormDB.AutoMigrate(
 		&models.User{},
 		&models.Room{},
@@ -68,6 +60,14 @@ func main() {
 		log.Fatal("auto migrate models", zap.Error(err))
 	}
 
+	if err := preparePublicIDColumns(gormDB); err != nil {
+		log.Fatal("prepare public_id columns", zap.Error(err))
+	}
+
+	if err := backfillPublicIDs(gormDB); err != nil {
+		log.Fatal("backfill public ids", zap.Error(err))
+	}
+
 	sqlDB, err := gormDB.DB()
 	if err != nil {
 		log.Fatal("get sql db", zap.Error(err))
diff --git a/go.mod b/go.mod
index 92abda1..eb7cfdf 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.25.0
 
 require (
 	github.com/gin-gonic/gin v1.12.0
+	github.com/google/uuid v1.6.0
 	github.com/joho/godotenv v1.5.1
 	github.com/oapi-codegen/runtime v1.3.1
 	go.uber.org/zap v1.27.1
@@ -24,7 +25,6 @@ require (
 	github.com/go-playground/validator/v10 v10.30.1 // indirect
 	github.com/goccy/go-json v0.10.5 // indirect
 	github.com/goccy/go-yaml v1.19.2 // indirect
-	github.com/google/uuid v1.6.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/pgx/v5 v5.6.0 // indirect
diff --git a/internal/repository/room_repository.go b/internal/repository/room_repository.go
index 1462b78..fb7b094 100644
--- a/internal/repository/room_repository.go
+++ b/internal/repository/room_repository.go
@@ -236,3 +236,29 @@ func (r *RoomRepository) CountPendingJoinRequestsByUser(ctx context.Context, use
 	}
 	return count, nil
 }
+
+/*为了避免多次查询数据库*/
+func (r *RoomRepository) CountMembersByRoomIDs(ctx context.Context, roomIDs []uint) (map[uint]int64, error) {
+	var results []struct {
+		RoomID uint
+		Count  int64
+	}
+
+	err := r.db.WithContext(ctx).
+		Model(&models.RoomMember{}).
+		Select("room_id, COUNT(*) as count").
+		Where("room_id IN ? AND status = ?", roomIDs, "joined").
+		Group("room_id").
+		Scan(&results).Error
+
+	if err != nil {
+		return nil, err
+	}
+
+	countMap := make(map[uint]int64)
+	for _, r := range results {
+		countMap[r.RoomID] = r.Count
+	}
+
+	return countMap, nil
+}
\ No newline at end of file
diff --git a/internal/service/room_service.go b/internal/service/room_service.go
index 5b59fb5..9ddc39b 100644
--- a/internal/service/room_service.go
+++ b/internal/service/room_service.go
@@ -7,6 +7,9 @@ import (
 
 	"github.com/QSCTech/SRTP-Backend/internal/repository"
 	"github.com/QSCTech/SRTP-Backend/models"
+
+	"errors"
+	"gorm.io/gorm"
 )
 
 type RoomService struct {
@@ -103,8 +106,56 @@ type UserStatsOutput struct {
 	PendingJoinRequestCount int64
 }
 
+/*基础功能：拿数据、加工成RoomCardItem*/
 func (s *RoomService) List(ctx context.Context, input ListRoomsInput) (*ListRoomsOutput, error) {
-	return nil, fmt.Errorf("room service List not implemented")
+	filter := repository.RoomFilter{
+		Keyword:      input.Keyword,
+		SportType:    input.SportType,
+		Campus:       input.Campus,
+		Date:         input.Date,
+		TimeRange:    input.TimeRange,
+		Organization: input.Organization,
+		Level:        input.Level,
+		Page:         int(input.Page),
+		PageSize:     int(input.PageSize),
+	}
+
+	result, err := s.repo.List(ctx, filter)
+	if err != nil {
+		return nil, err
+	}
+
+	rooms := result.Items
+
+	roomIDs := make([]uint, 0, len(rooms))
+	for _, r := range rooms {
+		roomIDs = append(roomIDs, r.ID)
+	}
+
+	countMap := make(map[uint]int64)
+	if len(roomIDs) > 0 {
+		countMap, err = s.repo.CountMembersByRoomIDs(ctx, roomIDs)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	items := make([]RoomCardItem, 0, len(rooms))
+	for _, r := range rooms {
+		count := countMap[r.ID]
+
+		items = append(items, RoomCardItem{
+			Room:               r,
+			CurrentMemberCount: int32(count),
+		})
+	}
+
+	return &ListRoomsOutput{
+		Page:     int32(input.Page),
+		PageSize: int32(input.PageSize),
+		Total:    result.Total,
+		Items:    items,
+	}, nil
 }
 
 func (s *RoomService) ListMineCreated(ctx context.Context, page, pageSize int) (*ListRoomsOutput, error) {
@@ -119,8 +170,24 @@ func (s *RoomService) GetMyStats(ctx context.Context) (*UserStatsOutput, error)
 	return nil, fmt.Errorf("room service GetMyStats not implemented")
 }
 
+/*基础功能：拿数据、判断*/
+
 func (s *RoomService) GetByID(ctx context.Context, id uint) (*models.Room, []models.RoomMember, error) {
-	return nil, nil, fmt.Errorf("room service GetByID not implemented")
+    room, err := s.repo.GetByID(ctx, id)
+    if err != nil {
+        if errors.Is(err, gorm.ErrRecordNotFound) {
+            var ErrRoomNotFound = errors.New("room not found")
+			return nil, nil, ErrRoomNotFound
+        }
+        return nil, nil, err
+    }
+
+    members, err := s.repo.GetMembersByRoomID(ctx, id)
+    if err != nil {
+        return nil, nil, err
+    }
+
+    return room, members, nil
 }
 
 func (s *RoomService) Create(ctx context.Context, input CreateRoomInput) (*models.Room, error) {