diff --git a/pkg/keyspace/tso_keyspace_group.go b/pkg/keyspace/tso_keyspace_group.go
index b9e8eb311ff..36b45f885d6 100644
--- a/pkg/keyspace/tso_keyspace_group.go
+++ b/pkg/keyspace/tso_keyspace_group.go
@@ -56,14 +56,20 @@ type GroupManager struct {
 	ctx    context.Context
 	cancel context.CancelFunc
 	wg     sync.WaitGroup
-	// the lock for the groups
+
 	sync.RWMutex
 	// groups is the cache of keyspace group related information.
 	// user kind -> keyspace group
 	groups map[endpoint.UserKind]*indexedHeap
+	// patrolKeyspaceAssignmentOnce is used to indicate whether we have patrolled all keyspaces
+	// and assign them to the keyspace groups.
+	patrolKeyspaceAssignmentOnce bool
 
 	// store is the storage for keyspace group related information.
-	store endpoint.KeyspaceGroupStorage
+	store interface {
+		endpoint.KeyspaceGroupStorage
+		endpoint.KeyspaceStorage
+	}
 
 	client *clientv3.Client
 
@@ -80,7 +86,15 @@ type GroupManager struct {
 }
 
 // NewKeyspaceGroupManager creates a Manager of keyspace group related data.
-func NewKeyspaceGroupManager(ctx context.Context, store endpoint.KeyspaceGroupStorage, client *clientv3.Client, clusterID uint64) *GroupManager {
+func NewKeyspaceGroupManager(
+	ctx context.Context,
+	store interface {
+		endpoint.KeyspaceGroupStorage
+		endpoint.KeyspaceStorage
+	},
+	client *clientv3.Client,
+	clusterID uint64,
+) *GroupManager {
 	ctx, cancel := context.WithCancel(ctx)
 	key := discovery.TSOPath(clusterID)
 	groups := make(map[endpoint.UserKind]*indexedHeap)
@@ -156,6 +170,38 @@ func (m *GroupManager) Close() {
 	m.wg.Wait()
 }
 
+// patrolKeyspaceAssignment is used to patrol all keyspaces and assign them to the keyspace groups.
+func (m *GroupManager) patrolKeyspaceAssignment() error {
+	m.Lock()
+	defer m.Unlock()
+	if m.patrolKeyspaceAssignmentOnce {
+		return nil
+	}
+	keyspaces, err := m.store.LoadRangeKeyspace(utils.DefaultKeyspaceID, 0)
+	if err != nil {
+		return err
+	}
+	config, err := m.getKeyspaceConfigByKindLocked(endpoint.Basic)
+	if err != nil {
+		return err
+	}
+	for _, ks := range keyspaces {
+		if ks == nil {
+			continue
+		}
+		groupID, err := strconv.ParseUint(config[TSOKeyspaceGroupIDKey], 10, 64)
+		if err != nil {
+			return err
+		}
+		err = m.updateKeyspaceForGroupLocked(endpoint.Basic, groupID, ks.GetId(), opAdd)
+		if err != nil {
+			return err
+		}
+	}
+	m.patrolKeyspaceAssignmentOnce = true
+	return nil
+}
+
 func (m *GroupManager) allocNodesToAllKeyspaceGroups() {
 	defer logutil.LogPanic()
 	defer m.wg.Done()
@@ -426,11 +472,18 @@ func (m *GroupManager) GetKeyspaceConfigByKind(userKind endpoint.UserKind) (map[
 	}
 	m.RLock()
 	defer m.RUnlock()
+	return m.getKeyspaceConfigByKindLocked(userKind)
+}
+
+func (m *GroupManager) getKeyspaceConfigByKindLocked(userKind endpoint.UserKind) (map[string]string, error) {
 	groups, ok := m.groups[userKind]
 	if !ok {
 		return map[string]string{}, errors.Errorf("user kind %s not found", userKind)
 	}
 	kg := groups.Top()
+	if kg == nil {
+		return map[string]string{}, errors.Errorf("no keyspace group for user kind %s", userKind)
+	}
 	id := strconv.FormatUint(uint64(kg.ID), 10)
 	config := map[string]string{
 		UserKindKey:           userKind.String(),
@@ -452,9 +505,13 @@ func (m *GroupManager) UpdateKeyspaceForGroup(userKind endpoint.UserKind, groupI
 
 	m.Lock()
 	defer m.Unlock()
-	kg := m.groups[userKind].Get(uint32(id))
+	return m.updateKeyspaceForGroupLocked(userKind, id, keyspaceID, mutation)
+}
+
+func (m *GroupManager) updateKeyspaceForGroupLocked(userKind endpoint.UserKind, groupID uint64, keyspaceID uint32, mutation int) error {
+	kg := m.groups[userKind].Get(uint32(groupID))
 	if kg == nil {
-		return errors.Errorf("keyspace group %d not found", id)
+		return errors.Errorf("keyspace group %d not found", groupID)
 	}
 	if kg.IsSplitting() {
 		return ErrKeyspaceGroupInSplit
@@ -535,11 +592,14 @@ func (m *GroupManager) UpdateKeyspaceGroup(oldGroupID, newGroupID string, oldUse
 // SplitKeyspaceGroupByID splits the keyspace group by ID into a new keyspace group with the given new ID.
 // And the keyspaces in the old keyspace group will be moved to the new keyspace group.
 func (m *GroupManager) SplitKeyspaceGroupByID(splitSourceID, splitTargetID uint32, keyspaces []uint32) error {
+	err := m.patrolKeyspaceAssignment()
+	if err != nil {
+		return err
+	}
 	var splitSourceKg, splitTargetKg *endpoint.KeyspaceGroup
 	m.Lock()
 	defer m.Unlock()
-	// TODO: avoid to split when the keyspaces is empty.
-	if err := m.store.RunInTxn(m.ctx, func(txn kv.Txn) (err error) {
+	if err = m.store.RunInTxn(m.ctx, func(txn kv.Txn) (err error) {
 		// Load the old keyspace group first.
 		splitSourceKg, err = m.store.LoadKeyspaceGroup(txn, splitSourceID)
 		if err != nil {
@@ -564,13 +624,15 @@ func (m *GroupManager) SplitKeyspaceGroupByID(splitSourceID, splitTargetID uint3
 		if splitTargetKg != nil {
 			return ErrKeyspaceGroupExists
 		}
+		keyspaceNum := len(keyspaces)
+		sourceKeyspaceNum := len(splitSourceKg.Keyspaces)
 		// Check if the keyspaces are all in the old keyspace group.
-		if len(keyspaces) > len(splitSourceKg.Keyspaces) {
+		if keyspaceNum == 0 || keyspaceNum > sourceKeyspaceNum {
 			return ErrKeyspaceNotInKeyspaceGroup
 		}
 		var (
-			oldKeyspaceMap = make(map[uint32]struct{}, len(splitSourceKg.Keyspaces))
-			newKeyspaceMap = make(map[uint32]struct{}, len(keyspaces))
+			oldKeyspaceMap = make(map[uint32]struct{}, sourceKeyspaceNum)
+			newKeyspaceMap = make(map[uint32]struct{}, keyspaceNum)
 		)
 		for _, keyspace := range splitSourceKg.Keyspaces {
 			oldKeyspaceMap[keyspace] = struct{}{}
@@ -582,7 +644,7 @@ func (m *GroupManager) SplitKeyspaceGroupByID(splitSourceID, splitTargetID uint3
 			newKeyspaceMap[keyspace] = struct{}{}
 		}
 		// Get the split keyspace group for the old keyspace group.
-		splitKeyspaces := make([]uint32, 0, len(splitSourceKg.Keyspaces)-len(keyspaces))
+		splitKeyspaces := make([]uint32, 0, sourceKeyspaceNum-keyspaceNum)
 		for _, keyspace := range splitSourceKg.Keyspaces {
 			if _, ok := newKeyspaceMap[keyspace]; !ok {
 				splitKeyspaces = append(splitKeyspaces, keyspace)
diff --git a/pkg/keyspace/tso_keyspace_group_test.go b/pkg/keyspace/tso_keyspace_group_test.go
index 6286a71b3aa..cfe035578e2 100644
--- a/pkg/keyspace/tso_keyspace_group_test.go
+++ b/pkg/keyspace/tso_keyspace_group_test.go
@@ -20,6 +20,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/pingcap/kvproto/pkg/keyspacepb"
 	"github.com/stretchr/testify/suite"
 	"github.com/tikv/pd/pkg/mcs/utils"
 	"github.com/tikv/pd/pkg/mock/mockcluster"
@@ -251,6 +252,9 @@ func (suite *keyspaceGroupTestSuite) TestKeyspaceGroupSplit() {
 	// split the keyspace group 1 to 4
 	err = suite.kgm.SplitKeyspaceGroupByID(1, 4, []uint32{333})
 	re.ErrorIs(err, ErrKeyspaceGroupNotEnoughReplicas)
+	// split the keyspace group 2 to 4 without giving any keyspace
+	err = suite.kgm.SplitKeyspaceGroupByID(2, 4, []uint32{})
+	re.ErrorIs(err, ErrKeyspaceNotInKeyspaceGroup)
 	// split the keyspace group 2 to 4
 	err = suite.kgm.SplitKeyspaceGroupByID(2, 4, []uint32{333})
 	re.NoError(err)
@@ -317,3 +321,31 @@ func (suite *keyspaceGroupTestSuite) TestKeyspaceGroupSplit() {
 	err = suite.kgm.SplitKeyspaceGroupByID(2, 5, []uint32{111, 222, 444})
 	re.ErrorIs(err, ErrKeyspaceNotInKeyspaceGroup)
 }
+
+func (suite *keyspaceGroupTestSuite) TestPatrolKeyspaceAssignment() {
+	re := suite.Require()
+	// Force the patrol to run once.
+	suite.kgm.patrolKeyspaceAssignmentOnce = false
+	// Create a keyspace group without any keyspace.
+	err := suite.kgm.CreateKeyspaceGroups([]*endpoint.KeyspaceGroup{
+		{
+			ID:       uint32(1),
+			UserKind: endpoint.Basic.String(),
+			Members:  make([]endpoint.KeyspaceGroupMember, 2),
+		},
+	})
+	re.NoError(err)
+	// Create a keyspace without any keyspace group.
+	now := time.Now().Unix()
+	err = suite.kg.saveNewKeyspace(&keyspacepb.KeyspaceMeta{
+		Id:             111,
+		Name:           "111",
+		State:          keyspacepb.KeyspaceState_ENABLED,
+		CreatedAt:      now,
+		StateChangedAt: now,
+	})
+	re.NoError(err)
+	// Split to see if the keyspace is attached to the group.
+	err = suite.kgm.SplitKeyspaceGroupByID(1, 2, []uint32{111})
+	re.NoError(err)
+}
diff --git a/tests/integrations/mcs/tso/keyspace_group_manager_test.go b/tests/integrations/mcs/tso/keyspace_group_manager_test.go
index 9cd46ad2d41..38000c257ce 100644
--- a/tests/integrations/mcs/tso/keyspace_group_manager_test.go
+++ b/tests/integrations/mcs/tso/keyspace_group_manager_test.go
@@ -83,6 +83,10 @@ func (suite *tsoKeyspaceGroupManagerTestSuite) TearDownTest() {
 
 func cleanupKeyspaceGroups(re *require.Assertions, server *tests.TestServer) {
 	for _, group := range handlersutil.MustLoadKeyspaceGroups(re, server, "0", "0") {
+		// Do not delete default keyspace group.
+		if group.ID == mcsutils.DefaultKeyspaceGroupID {
+			continue
+		}
 		handlersutil.MustDeleteKeyspaceGroup(re, server, group.ID)
 	}
 }