diff --git a/expression/expr_to_pb_test.go b/expression/expr_to_pb_test.go
index b215fc499cd1f..037d706a2f2b3 100644
--- a/expression/expr_to_pb_test.go
+++ b/expression/expr_to_pb_test.go
@@ -724,6 +724,109 @@ func (s *testEvaluatorSuite) TestExprPushDownToFlash(c *C) {
 	c.Assert(err, IsNil)
 	exprs = append(exprs, function)
 
+<<<<<<< HEAD
+=======
+	// CastStringAsReal
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeDouble), stringColumn)
+	c.Assert(err, IsNil)
+	exprs = append(exprs, function)
+
+	// Substring2ArgsUTF8
+	function, err = NewFunction(mock.NewContext(), ast.Substr, types.NewFieldType(mysql.TypeString), stringColumn, intColumn)
+	c.Assert(err, IsNil)
+	exprs = append(exprs, function)
+
+	// Substring3ArgsUTF8
+	function, err = NewFunction(mock.NewContext(), ast.Substr, types.NewFieldType(mysql.TypeString), stringColumn, intColumn, intColumn)
+	c.Assert(err, IsNil)
+	exprs = append(exprs, function)
+
+	// ScalarFuncSig_RoundReal
+	function, err = NewFunction(mock.NewContext(), ast.Round, types.NewFieldType(mysql.TypeDouble), realColumn)
+	c.Assert(err, IsNil)
+	exprs = append(exprs, function)
+
+	// ScalarFuncSig_RoundInt
+	function, err = NewFunction(mock.NewContext(), ast.Round, types.NewFieldType(mysql.TypeLonglong), intColumn)
+	c.Assert(err, IsNil)
+	exprs = append(exprs, function)
+
+	// concat
+	function, err = NewFunction(mock.NewContext(), ast.Concat, types.NewFieldType(mysql.TypeString), stringColumn, intColumn, realColumn)
+	c.Assert(err, IsNil)
+	exprs = append(exprs, function)
+
+	// UnixTimestampCurrent
+	function, err = NewFunction(mock.NewContext(), ast.UnixTimestamp, types.NewFieldType(mysql.TypeLonglong))
+	c.Assert(err, IsNil)
+	_, ok := function.(*Constant)
+	c.Assert(ok, IsTrue)
+
+	// UnixTimestampInt
+	datetimeColumn.RetType.Decimal = 0
+	function, err = NewFunction(mock.NewContext(), ast.UnixTimestamp, types.NewFieldType(mysql.TypeLonglong), datetimeColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_UnixTimestampInt)
+	exprs = append(exprs, function)
+
+	// UnixTimestampDecimal
+	datetimeColumn.RetType.Decimal = types.UnspecifiedLength
+	function, err = NewFunction(mock.NewContext(), ast.UnixTimestamp, types.NewFieldType(mysql.TypeNewDecimal), datetimeColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_UnixTimestampDec)
+	exprs = append(exprs, function)
+
+	// Year
+	function, err = NewFunction(mock.NewContext(), ast.Year, types.NewFieldType(mysql.TypeLonglong), datetimeColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_Year)
+	exprs = append(exprs, function)
+
+	// Day
+	function, err = NewFunction(mock.NewContext(), ast.Day, types.NewFieldType(mysql.TypeLonglong), datetimeColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_DayOfMonth)
+	exprs = append(exprs, function)
+
+	// Datediff
+	function, err = NewFunction(mock.NewContext(), ast.DateDiff, types.NewFieldType(mysql.TypeLonglong), datetimeColumn, datetimeColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_DateDiff)
+	exprs = append(exprs, function)
+
+	// Datesub
+	function, err = NewFunction(mock.NewContext(), ast.DateSub, types.NewFieldType(mysql.TypeDatetime), datetimeColumn, intColumn, stringColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_SubDateDatetimeInt)
+	exprs = append(exprs, function)
+	function, err = NewFunction(mock.NewContext(), ast.DateSub, types.NewFieldType(mysql.TypeDatetime), stringColumn, intColumn, stringColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_SubDateStringInt)
+	exprs = append(exprs, function)
+	function, err = NewFunction(mock.NewContext(), ast.SubDate, types.NewFieldType(mysql.TypeDatetime), datetimeColumn, intColumn, stringColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_SubDateDatetimeInt)
+	exprs = append(exprs, function)
+
+	// castTimeAsString:
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeString), datetimeColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_CastTimeAsString)
+	exprs = append(exprs, function)
+
+	// concat_ws
+	function, err = NewFunction(mock.NewContext(), ast.ConcatWS, types.NewFieldType(mysql.TypeString), stringColumn, stringColumn, stringColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_ConcatWS)
+	exprs = append(exprs, function)
+
+	// StrToDateDateTime
+	function, err = NewFunction(mock.NewContext(), ast.StrToDate, types.NewFieldType(mysql.TypeDatetime), stringColumn, stringColumn)
+	c.Assert(err, IsNil)
+	c.Assert(function.(*ScalarFunction).Function.PbCode(), Equals, tipb.ScalarFuncSig_StrToDateDatetime)
+	exprs = append(exprs, function)
+
+>>>>>>> 6154335ac... expression: Support push function year,day,datediff,datesub,castTimeAsString,concat_ws down to TiFlash. (#25097)
 	canPush := CanExprsPushDown(sc, exprs, client, kv.TiFlash)
 	c.Assert(canPush, Equals, true)
 
diff --git a/expression/expression.go b/expression/expression.go
index 26bf0fb6e18bf..4cf0a24d0cde8 100644
--- a/expression/expression.go
+++ b/expression/expression.go
@@ -1101,6 +1101,7 @@ func canFuncBePushed(sf *ScalarFunction, storeType kv.StoreType) bool {
 			ret = true
 		}
 	case
+<<<<<<< HEAD
 		ast.Substring,
 		ast.Substr:
 		switch sf.Function.PbCode() {
@@ -1111,6 +1112,60 @@ func canFuncBePushed(sf *ScalarFunction, storeType kv.StoreType) bool {
 		}
 	case ast.Rand:
 		switch sf.Function.PbCode() {
+=======
+		ast.LogicOr, ast.LogicAnd, ast.UnaryNot, ast.BitNeg, ast.Xor, ast.And, ast.Or,
+		ast.GE, ast.LE, ast.EQ, ast.NE, ast.LT, ast.GT, ast.In, ast.IsNull, ast.Like,
+		ast.Plus, ast.Minus, ast.Div, ast.Mul, /*ast.Mod,*/
+		ast.If, ast.Ifnull, ast.Case,
+		ast.Concat, ast.ConcatWS,
+		ast.Year, ast.Month, ast.Day,
+		ast.DateDiff, ast.TimestampDiff, ast.DateFormat, ast.FromUnixTime,
+		ast.JSONLength:
+		return true
+	case ast.Substr, ast.Substring:
+		switch function.Function.PbCode() {
+		case
+			tipb.ScalarFuncSig_Substring2ArgsUTF8,
+			tipb.ScalarFuncSig_Substring3ArgsUTF8:
+			return true
+		}
+	case ast.Cast:
+		switch function.Function.PbCode() {
+		case tipb.ScalarFuncSig_CastIntAsInt, tipb.ScalarFuncSig_CastIntAsReal, tipb.ScalarFuncSig_CastIntAsDecimal, tipb.ScalarFuncSig_CastIntAsString, tipb.ScalarFuncSig_CastIntAsTime,
+			tipb.ScalarFuncSig_CastRealAsInt, tipb.ScalarFuncSig_CastRealAsReal, tipb.ScalarFuncSig_CastRealAsDecimal, tipb.ScalarFuncSig_CastRealAsString, tipb.ScalarFuncSig_CastRealAsTime,
+			tipb.ScalarFuncSig_CastStringAsInt, tipb.ScalarFuncSig_CastStringAsReal, tipb.ScalarFuncSig_CastStringAsDecimal, tipb.ScalarFuncSig_CastStringAsString, tipb.ScalarFuncSig_CastStringAsTime,
+			tipb.ScalarFuncSig_CastDecimalAsInt /*, tipb.ScalarFuncSig_CastDecimalAsReal*/, tipb.ScalarFuncSig_CastDecimalAsDecimal, tipb.ScalarFuncSig_CastDecimalAsString, tipb.ScalarFuncSig_CastDecimalAsTime,
+			tipb.ScalarFuncSig_CastTimeAsInt /*, tipb.ScalarFuncSig_CastTimeAsReal*/, tipb.ScalarFuncSig_CastTimeAsDecimal, tipb.ScalarFuncSig_CastTimeAsTime, tipb.ScalarFuncSig_CastTimeAsString:
+			return true
+		}
+	case ast.DateAdd, ast.AddDate:
+		switch function.Function.PbCode() {
+		case tipb.ScalarFuncSig_AddDateDatetimeInt, tipb.ScalarFuncSig_AddDateStringInt:
+			return true
+		}
+	case ast.DateSub, ast.SubDate:
+		switch function.Function.PbCode() {
+		case tipb.ScalarFuncSig_SubDateDatetimeInt, tipb.ScalarFuncSig_SubDateStringInt:
+			return true
+		}
+	case ast.UnixTimestamp:
+		switch function.Function.PbCode() {
+		case tipb.ScalarFuncSig_UnixTimestampInt, tipb.ScalarFuncSig_UnixTimestampDec:
+			return true
+		}
+	case ast.Round:
+		switch function.Function.PbCode() {
+		case tipb.ScalarFuncSig_RoundInt, tipb.ScalarFuncSig_RoundReal:
+			return true
+		}
+	case ast.Extract:
+		switch function.Function.PbCode() {
+		case tipb.ScalarFuncSig_ExtractDatetime:
+			return true
+		}
+	case ast.StrToDate:
+		switch function.Function.PbCode() {
+>>>>>>> 6154335ac... expression: Support push function year,day,datediff,datesub,castTimeAsString,concat_ws down to TiFlash. (#25097)
 		case
 			tipb.ScalarFuncSig_RandWithSeedFirstGen:
 			ret = true