diff --git a/ddl/db_change_test.go b/ddl/db_change_test.go
index 6de1376e2b75b..cf11036a9935e 100644
--- a/ddl/db_change_test.go
+++ b/ddl/db_change_test.go
@@ -1719,8 +1719,6 @@ func TestCreateUniqueExpressionIndex(t *testing.T) {
 
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
-	// TODO: Will check why tidb_ddl_enable_fast_reorg could not default be on in another PR.
-	tk.MustExec("set global tidb_ddl_enable_fast_reorg = 0;")
 	tk.MustExec("create table t(a int default 0, b int default 0)")
 	tk.MustExec("insert into t values (1, 1), (2, 2), (3, 3), (4, 4)")
 
@@ -1740,8 +1738,6 @@ func TestCreateUniqueExpressionIndex(t *testing.T) {
 		if checkErr != nil {
 			return
 		}
-		err := originalCallback.OnChanged(nil)
-		require.NoError(t, err)
 		switch job.SchemaState {
 		case model.StateDeleteOnly:
 			for _, sql := range stateDeleteOnlySQLs {
diff --git a/ddl/index_change_test.go b/ddl/index_change_test.go
index 85352cb6d08d1..f9dcc99154dc5 100644
--- a/ddl/index_change_test.go
+++ b/ddl/index_change_test.go
@@ -37,8 +37,6 @@ func TestIndexChange(t *testing.T) {
 	ddl.SetWaitTimeWhenErrorOccurred(1 * time.Microsecond)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
-	// TODO: Will check why tidb_ddl_enable_fast_reorg could not default be on in another PR.
-	tk.MustExec("set global tidb_ddl_enable_fast_reorg = 0;")
 	tk.MustExec("create table t (c1 int primary key, c2 int)")
 	tk.MustExec("insert t values (1, 1), (2, 2), (3, 3);")
 
@@ -221,6 +219,7 @@ func checkAddWriteOnlyForAddIndex(ctx sessionctx.Context, delOnlyTbl, writeOnlyT
 }
 
 func checkAddPublicForAddIndex(ctx sessionctx.Context, writeTbl, publicTbl table.Table) error {
+	var err1 error
 	// WriteOnlyTable: insert t values (6, 6)
 	err := sessiontxn.NewTxn(context.Background(), ctx)
 	if err != nil {
@@ -231,7 +230,11 @@ func checkAddPublicForAddIndex(ctx sessionctx.Context, writeTbl, publicTbl table
 		return errors.Trace(err)
 	}
 	err = checkIndexExists(ctx, publicTbl, 6, 6, true)
-	if err != nil {
+	if ddl.IsEnableFastReorg() {
+		// Need check temp index also.
+		err1 = checkIndexExists(ctx, writeTbl, 6, 6, true)
+	}
+	if err != nil && err1 != nil {
 		return errors.Trace(err)
 	}
 	// PublicTable: insert t values (7, 7)
@@ -250,10 +253,18 @@ func checkAddPublicForAddIndex(ctx sessionctx.Context, writeTbl, publicTbl table
 		return errors.Trace(err)
 	}
 	err = checkIndexExists(ctx, publicTbl, 5, 7, true)
-	if err != nil {
+	if ddl.IsEnableFastReorg() {
+		// Need check temp index also.
+		err1 = checkIndexExists(ctx, writeTbl, 5, 7, true)
+	}
+	if err != nil && err1 != nil {
 		return errors.Trace(err)
 	}
-	err = checkIndexExists(ctx, publicTbl, 7, 7, false)
+	if ddl.IsEnableFastReorg() {
+		err = checkIndexExists(ctx, writeTbl, 7, 7, false)
+	} else {
+		err = checkIndexExists(ctx, publicTbl, 7, 7, false)
+	}
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -283,7 +294,11 @@ func checkAddPublicForAddIndex(ctx sessionctx.Context, writeTbl, publicTbl table
 		idxVal := row[1].GetInt64()
 		handle := row[0].GetInt64()
 		err = checkIndexExists(ctx, publicTbl, idxVal, handle, true)
-		if err != nil {
+		if ddl.IsEnableFastReorg() {
+			// Need check temp index also.
+			err1 = checkIndexExists(ctx, writeTbl, idxVal, handle, true)
+		}
+		if err != nil && err1 != nil {
 			return errors.Trace(err)
 		}
 	}
diff --git a/ddl/index_merge_tmp_test.go b/ddl/index_merge_tmp_test.go
index 8dae95e590438..389339ac15ad4 100644
--- a/ddl/index_merge_tmp_test.go
+++ b/ddl/index_merge_tmp_test.go
@@ -259,3 +259,75 @@ func TestPessimisticAmendIncompatibleWithFastReorg(t *testing.T) {
 	tk.MustGetErrMsg("set @@tidb_enable_amend_pessimistic_txn = 1;",
 		"amend pessimistic transactions is not compatible with tidb_ddl_enable_fast_reorg")
 }
+
+// TestCreateUniqueIndexKeyExist this case will test below things:
+// Create one unique index idx((a*b+1));
+// insert (0, 6) and delete it;
+// insert (0, 9), it should be successful;
+// Should check temp key exist and skip deleted mark
+// The error returned below:
+// Error:      	Received unexpected error:
+//
+//	[kv:1062]Duplicate entry '1' for key 't.idx'
+func TestCreateUniqueIndexKeyExist(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomain(t)
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("create table t(a int default 0, b int default 0)")
+	tk.MustExec("insert into t values (1, 1), (2, 2), (3, 3), (4, 4)")
+
+	tk1 := testkit.NewTestKit(t, store)
+	tk1.MustExec("use test")
+
+	stateDeleteOnlySQLs := []string{"insert into t values (5, 5)", "begin pessimistic;", "insert into t select * from t", "rollback", "insert into t set b = 6", "update t set b = 7 where a = 1", "delete from t where b = 4"}
+
+	// If waitReorg timeout, the worker may enter writeReorg more than 2 times.
+	reorgTime := 0
+	d := dom.DDL()
+	originalCallback := d.GetHook()
+	defer d.SetHook(originalCallback)
+	callback := &ddl.TestDDLCallback{}
+	onJobUpdatedExportedFunc := func(job *model.Job) {
+		if t.Failed() {
+			return
+		}
+		var err error
+		switch job.SchemaState {
+		case model.StateDeleteOnly:
+			for _, sql := range stateDeleteOnlySQLs {
+				_, err = tk1.Exec(sql)
+				assert.NoError(t, err)
+			}
+			// (1, 7), (2, 2), (3, 3), (5, 5), (0, 6)
+		case model.StateWriteOnly:
+			_, err = tk1.Exec("insert into t values (8, 8)")
+			assert.NoError(t, err)
+			_, err = tk1.Exec("update t set b = 7 where a = 2")
+			assert.NoError(t, err)
+			_, err = tk1.Exec("delete from t where b = 3")
+			assert.NoError(t, err)
+			// (1, 7), (2, 7), (5, 5), (0, 6), (8, 8)
+		case model.StateWriteReorganization:
+			if reorgTime < 1 {
+				reorgTime++
+			} else {
+				return
+			}
+			_, err = tk1.Exec("insert into t values (10, 10)")
+			assert.NoError(t, err)
+			_, err = tk1.Exec("delete from t where b = 6")
+			assert.NoError(t, err)
+			_, err = tk1.Exec("insert into t set b = 9")
+			assert.NoError(t, err)
+			_, err = tk1.Exec("update t set b = 7 where a = 5")
+			assert.NoError(t, err)
+			// (1, 7), (2, 7), (5, 7), (8, 8), (10, 10), (0, 9)
+		}
+	}
+	callback.OnJobUpdatedExported.Store(&onJobUpdatedExportedFunc)
+	d.SetHook(callback)
+	tk.MustExec("alter table t add unique index idx((a*b+1))")
+	tk.MustExec("admin check table t")
+	tk.MustQuery("select * from t order by a, b").Check(testkit.Rows("0 9", "1 7", "2 7", "5 7", "8 8", "10 10"))
+}
diff --git a/executor/batch_checker.go b/executor/batch_checker.go
index d3820ecb0d08c..79a6748b2d5c3 100644
--- a/executor/batch_checker.go
+++ b/executor/batch_checker.go
@@ -180,6 +180,10 @@ func getKeysNeedCheckOneRow(ctx sessionctx.Context, t table.Table, row []types.D
 		if !distinct {
 			continue
 		}
+		// If index is used ingest ways, then we should check key from temp index.
+		if v.Meta().BackfillState != model.BackfillStateInapplicable {
+			_, key, _ = tables.GenTempIdxKeyByState(v.Meta(), key)
+		}
 		colValStr, err1 := formatDataForDupError(colVals)
 		if err1 != nil {
 			return nil, err1
diff --git a/executor/insert.go b/executor/insert.go
index 2450f0a117f70..7e17fabcfe957 100644
--- a/executor/insert.go
+++ b/executor/insert.go
@@ -15,6 +15,7 @@
 package executor
 
 import (
+	"bytes"
 	"context"
 	"encoding/hex"
 	"fmt"
@@ -31,6 +32,7 @@ import (
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/pingcap/tidb/parser/terror"
 	"github.com/pingcap/tidb/table"
+	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/tablecodec"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
@@ -262,6 +264,14 @@ func (e *InsertExec) batchUpdateDupRows(ctx context.Context, newRows [][]types.D
 				}
 				return err
 			}
+			// Since the temp index stores deleted key with marked 'deleteu' for unique key at the end
+			// of value, So if return a key we check and skip deleted key.
+			if tablecodec.IsTempIndexKey(uk.newKey) {
+				rowVal := val[:len(val)-1]
+				if bytes.Equal(rowVal, tables.DeleteMarkerUnique) {
+					continue
+				}
+			}
 			handle, err := tablecodec.DecodeHandleInUniqueIndexValue(val, uk.commonHandle)
 			if err != nil {
 				return err
diff --git a/table/tables/index.go b/table/tables/index.go
index 9fc1042a110fd..b3a481efba29f 100644
--- a/table/tables/index.go
+++ b/table/tables/index.go
@@ -15,7 +15,9 @@
 package tables
 
 import (
+	"bytes"
 	"context"
+	"errors"
 	"sync"
 
 	"github.com/opentracing/opentracing-go"
@@ -127,7 +129,7 @@ func (c *index) Create(sctx sessionctx.Context, txn kv.Transaction, indexedValue
 		keyIsTempIdxKey bool
 	)
 	if !opt.FromBackFill {
-		key, tempKey, keyVer = genTempIdxKeyByState(c.idxInfo, key)
+		key, tempKey, keyVer = GenTempIdxKeyByState(c.idxInfo, key)
 		if keyVer == TempIndexKeyTypeBackfill {
 			key, tempKey = tempKey, nil
 			keyIsTempIdxKey = true
@@ -226,11 +228,26 @@ func (c *index) Create(sctx sessionctx.Context, txn kv.Transaction, indexedValue
 	}
 	if err != nil || len(value) == 0 {
 		lazyCheck := sctx.GetSessionVars().LazyCheckKeyNotExists() && err != nil
+		var needPresumeKey tempIndexKeyState
 		if keyIsTempIdxKey {
 			idxVal = append(idxVal, keyVer)
+			needPresumeKey, _, err = KeyExistInTempIndex(ctx, txn, key, distinct, h, c.tblInfo.IsCommonHandle)
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			if len(tempKey) > 0 {
+				needPresumeKey, _, err = KeyExistInTempIndex(ctx, txn, tempKey, distinct, h, c.tblInfo.IsCommonHandle)
+				if err != nil {
+					return nil, err
+				}
+			}
 		}
 		if lazyCheck {
-			flags := []kv.FlagsOp{kv.SetPresumeKeyNotExists}
+			var flags []kv.FlagsOp
+			if needPresumeKey != KeyInTempIndexIsDeleted {
+				flags = []kv.FlagsOp{kv.SetPresumeKeyNotExists}
+			}
 			if !vars.ConstraintCheckInPlacePessimistic && vars.TxnCtx.IsPessimistic && vars.InTxn() &&
 				!vars.InRestrictedSQL && vars.ConnectionID > 0 {
 				flags = append(flags, kv.SetNeedConstraintCheckInPrewrite)
@@ -244,7 +261,7 @@ func (c *index) Create(sctx sessionctx.Context, txn kv.Transaction, indexedValue
 		}
 		if len(tempKey) > 0 {
 			idxVal = append(idxVal, keyVer)
-			if lazyCheck {
+			if lazyCheck && needPresumeKey != KeyInTempIndexIsDeleted {
 				err = txn.GetMemBuffer().SetWithFlags(tempKey, idxVal, kv.SetPresumeKeyNotExists)
 			} else {
 				err = txn.GetMemBuffer().Set(tempKey, idxVal)
@@ -285,7 +302,7 @@ func (c *index) Delete(sc *stmtctx.StatementContext, txn kv.Transaction, indexed
 		return err
 	}
 
-	key, tempKey, tempKeyVer := genTempIdxKeyByState(c.idxInfo, key)
+	key, tempKey, tempKeyVer := GenTempIdxKeyByState(c.idxInfo, key)
 
 	if distinct {
 		if len(key) > 0 {
@@ -336,9 +353,9 @@ const (
 	TempIndexKeyTypeMerge byte = 'm'
 )
 
-// genTempIdxKeyByState is used to get the key version and the temporary key.
+// GenTempIdxKeyByState is used to get the key version and the temporary key.
 // The tempKeyVer means the temp index key/value version.
-func genTempIdxKeyByState(indexInfo *model.IndexInfo, indexKey kv.Key) (key, tempKey kv.Key, tempKeyVer byte) {
+func GenTempIdxKeyByState(indexInfo *model.IndexInfo, indexKey kv.Key) (key, tempKey kv.Key, tempKeyVer byte) {
 	if indexInfo.State != model.StatePublic {
 		switch indexInfo.BackfillState {
 		case model.BackfillStateInapplicable:
@@ -364,6 +381,28 @@ func (c *index) Exist(sc *stmtctx.StatementContext, txn kv.Transaction, indexedV
 		return false, nil, err
 	}
 
+	var (
+		tempKey []byte
+		keyVer  byte
+	)
+	// If index current is in creating status and using ingest mode, we need first
+	// check key exist status in temp index.
+	key, tempKey, keyVer = GenTempIdxKeyByState(c.idxInfo, key)
+	if keyVer != TempIndexKeyTypeNone {
+		KeyExistInfo, h1, err1 := KeyExistInTempIndex(context.TODO(), txn, tempKey, distinct, h, c.tblInfo.IsCommonHandle)
+		if err1 != nil {
+			return false, nil, err
+		}
+		switch KeyExistInfo {
+		case KeyInTempIndexNotExist, KeyInTempIndexIsDeleted:
+			return false, nil, nil
+		case KeyInTempIndexConflict:
+			return true, h1, kv.ErrKeyExists
+		case KeyInTempIndexIsItself:
+			return true, h, nil
+		}
+	}
+
 	value, err := txn.Get(context.TODO(), key)
 	if kv.IsErrNotFound(err) {
 		return false, nil, nil
@@ -463,3 +502,64 @@ func TryAppendCommonHandleRowcodecColInfos(colInfo []rowcodec.ColInfo, tblInfo *
 	}
 	return colInfo
 }
+
+type tempIndexKeyState byte
+
+const (
+	// KeyInTempIndexUnknown whether the key exists or not in temp index is unknown.
+	KeyInTempIndexUnknown tempIndexKeyState = iota
+	// KeyInTempIndexNotExist the key is not exist in temp index.
+	KeyInTempIndexNotExist
+	// KeyInTempIndexIsDeleted the key is marked deleted in temp index.
+	KeyInTempIndexIsDeleted
+	// KeyInTempIndexIsItself the key is correlated to itself in temp index.
+	KeyInTempIndexIsItself
+	// KeyInTempIndexConflict the key is conflict in temp index.
+	KeyInTempIndexConflict
+)
+
+// KeyExistInTempIndex is used to check the unique key exist status in temp index.
+func KeyExistInTempIndex(ctx context.Context, txn kv.Transaction, key kv.Key, distinct bool, h kv.Handle, IsCommonHandle bool) (tempIndexKeyState, kv.Handle, error) {
+	// Only check temp index key.
+	if !tablecodec.IsTempIndexKey(key) {
+		return KeyInTempIndexUnknown, nil, nil
+	}
+	value, err := txn.Get(ctx, key)
+	if kv.IsErrNotFound(err) {
+		return KeyInTempIndexNotExist, nil, nil
+	}
+	if err != nil {
+		return KeyInTempIndexUnknown, nil, err
+	}
+
+	// Since KeyExistInTempIndex only accept temp index key, so the value length should great than 1 for key version.
+	if len(value) < 1 {
+		return KeyInTempIndexUnknown, nil, errors.New("temp index value length should great than 1")
+	}
+	length := len(value)
+	// Firstly, we will remove the last byte of key version.
+	// It should be TempIndexKeyTypeBackfill or TempIndexKeyTypeMerge.
+	value = value[:length-1]
+	if distinct {
+		if bytes.Equal(value, DeleteMarkerUnique) {
+			return KeyInTempIndexIsDeleted, nil, nil
+		}
+	} else {
+		if bytes.Equal(value, DeleteMarker) {
+			return KeyInTempIndexIsDeleted, nil, nil
+		}
+	}
+
+	// Check if handle equal.
+	var handle kv.Handle
+	if distinct {
+		handle, err = tablecodec.DecodeHandleInUniqueIndexValue(value, IsCommonHandle)
+		if err != nil {
+			return KeyInTempIndexUnknown, nil, err
+		}
+		if !handle.Equal(h) {
+			return KeyInTempIndexConflict, handle, kv.ErrKeyExists
+		}
+	}
+	return KeyInTempIndexIsItself, handle, nil
+}
diff --git a/tablecodec/tablecodec.go b/tablecodec/tablecodec.go
index b9400b0271d41..e45576b9d0674 100644
--- a/tablecodec/tablecodec.go
+++ b/tablecodec/tablecodec.go
@@ -1143,6 +1143,20 @@ func TempIndexKey2IndexKey(originIdxID int64, tempIdxKey []byte) {
 	binary.BigEndian.PutUint64(tempIdxKey[prefixLen:], eid)
 }
 
+// IsTempIndexKey check whether the input key is for a temp index.
+func IsTempIndexKey(indexKey []byte) bool {
+	var (
+		indexIDKey  []byte
+		indexID     int64
+		tempIndexID int64
+	)
+	// Get encoded indexID from key, Add uint64 8 byte length.
+	indexIDKey = indexKey[prefixLen : prefixLen+8]
+	indexID = codec.DecodeCmpUintToInt(binary.BigEndian.Uint64(indexIDKey))
+	tempIndexID = int64(TempIndexPrefix) | indexID
+	return tempIndexID == indexID
+}
+
 // GenIndexValuePortal is the portal for generating index value.
 // Value layout:
 //