diff --git a/executor/errors.go b/executor/errors.go
index a48152f0acdfe..89f97057c8afb 100644
--- a/executor/errors.go
+++ b/executor/errors.go
@@ -51,6 +51,7 @@ var (
 	ErrBadDB                       = terror.ClassExecutor.New(mysql.ErrBadDB, mysql.MySQLErrName[mysql.ErrBadDB])
 	ErrWrongObject                 = terror.ClassExecutor.New(mysql.ErrWrongObject, mysql.MySQLErrName[mysql.ErrWrongObject])
 	ErrRoleNotGranted              = terror.ClassPrivilege.New(mysql.ErrRoleNotGranted, mysql.MySQLErrName[mysql.ErrRoleNotGranted])
+	ErrNotValidPassword            = terror.ClassExecutor.New(mysql.ErrNotValidPassword, mysql.MySQLErrName[mysql.ErrNotValidPassword])
 	ErrDeadlock                    = terror.ClassExecutor.New(mysql.ErrLockDeadlock, mysql.MySQLErrName[mysql.ErrLockDeadlock])
 	ErrQueryInterrupted            = terror.ClassExecutor.New(mysql.ErrQueryInterrupted, mysql.MySQLErrName[mysql.ErrQueryInterrupted])
 )
@@ -69,6 +70,7 @@ func init() {
 		mysql.ErrTableaccessDenied:           mysql.ErrTableaccessDenied,
 		mysql.ErrBadDB:                       mysql.ErrBadDB,
 		mysql.ErrWrongObject:                 mysql.ErrWrongObject,
+		mysql.ErrNotValidPassword:            mysql.ErrNotValidPassword,
 		mysql.ErrLockDeadlock:                mysql.ErrLockDeadlock,
 		mysql.ErrQueryInterrupted:            mysql.ErrQueryInterrupted,
 	}
diff --git a/expression/builtin_encryption.go b/expression/builtin_encryption.go
index 85083cc5cfeb3..de5c253b1566a 100644
--- a/expression/builtin_encryption.go
+++ b/expression/builtin_encryption.go
@@ -26,7 +26,10 @@ import (
 	"fmt"
 	"hash"
 	"io"
+	"strconv"
 	"strings"
+	"unicode"
+	"unicode/utf8"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/auth"
@@ -76,6 +79,15 @@ var (
 // ivSize indicates the initialization vector supplied to aes_decrypt
 const ivSize = aes.BlockSize
 
+// the max length of a password is 100 in mysql
+const maxPwdLength int64 = 100
+
+// VALIDATE_PASSWORD_STRENGTH() will return 0 when the length of a password is less than minPwsLength
+const minPwdLength int64 = 4
+
+// Differential score between levels in password test
+const differentialScore int64 = 25
+
 // aesModeAttr indicates that the key length and iv attribute for specific block_encryption_mode.
 // keySize is the key length in bits and mode is the encryption mode.
 // ivRequired indicates that initialization vector is required or not.
@@ -895,10 +907,160 @@ func (b *builtinUncompressedLengthSig) evalInt(row chunk.Row) (int64, bool, erro
 	return int64(len), false, nil
 }
 
+func reverse(s string) string {
+	runes := []rune(s)
+	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+	return string(runes)
+}
+
+func validateByUser(s *variable.SessionVars, psw string) (bool, error) {
+	v, err := variable.GetGlobalSystemVar(s, variable.ValidatePasswordCheckUserName)
+	if err != nil || strings.EqualFold(v, "OFF") {
+		return err == nil, err
+	}
+	if s.User == nil {
+		return true, nil
+	}
+	if n := s.User.Username; n != "" {
+		if psw == n || psw == reverse(n) {
+			return false, nil
+		}
+	}
+	if n := s.User.AuthUsername; n != "" {
+		if psw == n || psw == reverse(n) {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+func validateByMixedDigitSpecial(s *variable.SessionVars, pwd string) (bool, error) {
+	// get system variables
+	v, err := variable.GetGlobalSystemVar(s, variable.ValidatePasswordMixedCaseCount)
+	if err != nil {
+		return false, err
+	}
+	minMixed, err := strconv.ParseInt(v, 10, 64)
+	if err != nil {
+		return false, err
+	}
+	v, err = variable.GetGlobalSystemVar(s, variable.ValidatePasswordNumberCount)
+	if err != nil {
+		return false, err
+	}
+	minDigit, err := strconv.ParseInt(v, 10, 64)
+	if err != nil {
+		return false, err
+	}
+	v, err = variable.GetGlobalSystemVar(s, variable.ValidatePasswordSpecialCharCount)
+	if err != nil {
+		return false, err
+	}
+	minSpecial, err := strconv.ParseInt(v, 10, 64)
+	if err != nil {
+		return false, err
+	}
+
+	numLower := int64(0)
+	numUpper := int64(0)
+	numDigit := int64(0)
+	numSpecial := int64(0)
+	for _, c := range pwd {
+		if unicode.IsLower(c) {
+			numLower++
+		} else if unicode.IsUpper(c) {
+			numUpper++
+		} else if unicode.IsDigit(c) {
+			numDigit++
+		} else {
+			numSpecial++
+		}
+	}
+
+	if numLower < minMixed || numUpper < minMixed || numDigit < minDigit || numSpecial < minSpecial {
+		return false, nil
+	}
+	return true, nil
+}
+
+// TODO: Support validating password by dictionary file
+func validateByDictionary(s *variable.SessionVars, pwd string) (bool, error) {
+	return true, nil
+}
+
 type validatePasswordStrengthFunctionClass struct {
 	baseFunctionClass
 }
 
 func (c *validatePasswordStrengthFunctionClass) getFunction(ctx sessionctx.Context, args []Expression) (builtinFunc, error) {
-	return nil, errFunctionNotExists.GenWithStackByArgs("FUNCTION", "VALIDATE_PASSWORD_STRENGTH")
+	if err := c.verifyArgs(args); err != nil {
+		return nil, err
+	}
+	bf := newBaseBuiltinFuncWithTp(ctx, args, types.ETInt, types.ETString)
+	bf.tp.Flag = mysql.MaxIntWidth
+	sig := &builtinValidatePasswordStrengthSig{bf}
+	return sig, nil
+}
+
+type builtinValidatePasswordStrengthSig struct {
+	baseBuiltinFunc
+}
+
+func (c *builtinValidatePasswordStrengthSig) Clone() builtinFunc {
+	newSig := &builtinValidatePasswordStrengthSig{}
+	newSig.cloneFrom(&c.baseBuiltinFunc)
+	return newSig
+}
+
+// evalInt evals VALIDATE_PASSWORD_STRENGTH(str).
+// See https://dev.mysql.com/doc/refman/5.7/en/encryption-functions.html#function_validate-password-strength
+func (c *builtinValidatePasswordStrengthSig) evalInt(row chunk.Row) (int64, bool, error) {
+	sv := c.ctx.GetSessionVars()
+	pwd, isNull, err := c.args[0].EvalString(c.ctx, row)
+	score := int64(0)
+
+	if isNull || err != nil {
+		return score, true, err
+	}
+
+	l := int64(utf8.RuneCountInString(pwd))
+	if l > maxPwdLength {
+		pwd = string([]rune(pwd)[0:maxPwdLength])
+	}
+
+	valid, err := validateByUser(sv, pwd)
+	if err != nil || !valid {
+		return score, err != nil, err
+	}
+
+	if l < minPwdLength {
+		return score, false, nil
+	}
+	score += differentialScore
+
+	v, err := variable.GetGlobalSystemVar(sv, variable.ValidatePasswordLength)
+	if err != nil {
+		return score, false, nil
+	}
+	valPwdLen, err := strconv.ParseInt(v, 10, 64)
+	if err != nil || l < valPwdLen {
+		return score, err != nil, err
+	}
+	score += differentialScore
+
+	valid, err = validateByMixedDigitSpecial(sv, pwd)
+	if err != nil || !valid {
+		return score, err != nil, err
+	}
+	score += differentialScore
+
+	valid, err = validateByDictionary(sv, pwd)
+	if err != nil || !valid {
+		return score, err != nil, nil
+	}
+	score += differentialScore
+
+	return score, false, nil
 }
diff --git a/expression/builtin_encryption_test.go b/expression/builtin_encryption_test.go
index 4a12f14f1a9af..10b710ba3a21d 100644
--- a/expression/builtin_encryption_test.go
+++ b/expression/builtin_encryption_test.go
@@ -493,3 +493,35 @@ func (s *testEvaluatorSuite) TestPassword(c *C) {
 	_, err := funcs[ast.PasswordFunc].getFunction(s.ctx, []Expression{Zero})
 	c.Assert(err, IsNil)
 }
+
+func (s *testEvaluatorSuite) TestValidatePasswordStrength(c *C) {
+	defer testleak.AfterTest(c)()
+	tests := []struct {
+		in     interface{}
+		expect int64
+	}{
+		{"", 0},
+		{"1", 0},
+		{"你好啊", 0},
+		{"pass", 25},
+		{"user123", 25},
+		{"你好世界", 25},
+		{"password", 50},
+		{"password0000", 50},
+		{"auth_user", 50},
+		{"你好世界你好世界", 50},
+		{"Pingcap123", 50},
+		{"Pingcap123_", 100},
+		{"password1A#", 100},
+		{"PA12wrd!#", 100},
+		{"PA00wrd!#", 100},
+	}
+
+	for _, t := range tests {
+		f, err := newFunctionForTest(s.ctx, ast.ValidatePasswordStrength, s.primitiveValsToConstants([]interface{}{t.in})...)
+		c.Assert(err, IsNil)
+		d, err := f.Eval(chunk.Row{})
+		c.Assert(err, IsNil)
+		c.Assert(d.GetInt64(), Equals, t.expect)
+	}
+}
diff --git a/expression/integration_test.go b/expression/integration_test.go
index 59bdae56242d7..81ba83e4955e3 100644
--- a/expression/integration_test.go
+++ b/expression/integration_test.go
@@ -4368,6 +4368,65 @@ func (s *testIntegrationSuite) TestIssue9325(c *C) {
 	result.Check(testkit.Rows("2019-02-16 14:19:59", "2019-02-16 14:20:01"))
 }
 
+func (s *testIntegrationSuite) TestFuncValidatePasswordStrength(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("set global validate_password_check_user_name = 'ON';")
+	tk.MustQuery("SELECT @@global.validate_password_check_user_name;").Check(testkit.Rows("1"))
+	err := tk.ExecToErr("SET @@session.validate_password_check_user_name= ON;")
+	c.Assert(err, ErrorMatches, "*Variable 'validate_password_check_user_name' is a GLOBAL variable and should be set with SET GLOBAL")
+	err = tk.ExecToErr("SET validate_password_check_user_name= ON;")
+	c.Assert(err, ErrorMatches, "*Variable 'validate_password_check_user_name' is a GLOBAL variable and should be set with SET GLOBAL")
+	tk.MustExec("SET @@global.validate_password_policy=LOW;")
+	tk.MustExec("SET @@global.validate_password_mixed_case_count=0;")
+	tk.MustExec("SET @@global.validate_password_number_count=0;")
+	tk.MustExec("SET @@global.validate_password_special_char_count=0;")
+	tk.MustExec("SET @@global.validate_password_length=0;")
+	tk.MustExec("SET @@global.validate_password_check_user_name= ON;")
+	tk.Se.GetSessionVars().User = &auth.UserIdentity{Username: "root", AuthUsername: "root"}
+	result := tk.MustQuery("SELECT VALIDATE_PASSWORD_STRENGTH('root') = 0;")
+	result.Check(testkit.Rows("1"))
+	result = tk.MustQuery("SELECT VALIDATE_PASSWORD_STRENGTH('toor') = 0;")
+	result.Check(testkit.Rows("1"))
+	result = tk.MustQuery("SELECT VALIDATE_PASSWORD_STRENGTH('Root') <> 0;")
+	result.Check(testkit.Rows("1"))
+	result = tk.MustQuery("SELECT VALIDATE_PASSWORD_STRENGTH('Toor') <> 0;")
+	result.Check(testkit.Rows("1"))
+	result = tk.MustQuery("SELECT VALIDATE_PASSWORD_STRENGTH('fooHoHo%1') <> 0;")
+	result.Check(testkit.Rows("1"))
+
+	err = tk.ExecToErr("SELECT VALIDATE_PASSWORD_STRENGTH('password', 0);")
+	c.Check(err, ErrorMatches, "*Incorrect parameter count in the call to native function 'validate_password_strength'")
+	err = tk.ExecToErr("SELECT VALIDATE_PASSWORD_STRENGTH();")
+	c.Check(err, ErrorMatches, "*Incorrect parameter count in the call to native function 'validate_password_strength'")
+
+	tk.MustExec("set global validate_password_length = 10;")
+	tk.MustExec("set global validate_password_mixed_case_count = 3;")
+	tk.MustExec("set global validate_password_number_count = 3;")
+	tk.MustExec("set global validate_password_special_char_count = 3;")
+	tk.Se.GetSessionVars().User = &auth.UserIdentity{Username: "user123", AuthUsername: "auth_user"}
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('user123')")
+	result.Check(testkit.Rows("0"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('321resu')")
+	result.Check(testkit.Rows("0"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('auth_user')")
+	result.Check(testkit.Rows("0"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('resu_htua')")
+	result.Check(testkit.Rows("0"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('password')")
+	result.Check(testkit.Rows("25"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('password12')")
+	result.Check(testkit.Rows("50"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('Pingcap123_')")
+	result.Check(testkit.Rows("50"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('PingcapPP123_')")
+	result.Check(testkit.Rows("50"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('PINGCAp123_')")
+	result.Check(testkit.Rows("50"))
+	result = tk.MustQuery("select VALIDATE_PASSWORD_STRENGTH('Pingcap_PP_123!')")
+	result.Check(testkit.Rows("100"))
+
+}
+
 func (s *testIntegrationSuite) TestIssue9710(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	getSAndMS := func(str string) (int, int) {
diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
index 9d8ade09e4748..1317df443e5f5 100644
--- a/sessionctx/variable/sysvar.go
+++ b/sessionctx/variable/sysvar.go
@@ -135,8 +135,14 @@ var defaultSysVars = []*SysVar{
 	{ScopeGlobal, "slave_pending_jobs_size_max", "16777216"},
 	{ScopeNone, "innodb_sync_array_size", "1"},
 	{ScopeSession, "rand_seed2", ""},
+	{ScopeGlobal, "validate_password_check_user_name", "OFF"},
+	{ScopeGlobal, "validate_password_dictionary_file", ""},
+	{ScopeGlobal, "validate_password_length", "8"},
+	{ScopeGlobal, "validate_password_mixed_case_count", "1"},
 	{ScopeGlobal, ValidatePasswordCheckUserName, "0"},
 	{ScopeGlobal, "validate_password_number_count", "1"},
+	{ScopeGlobal, "validate_password_policy", "MEDIUM"},
+	{ScopeGlobal, "validate_password_special_char_count", "1"},
 	{ScopeSession, "gtid_next", ""},
 	{ScopeGlobal | ScopeSession, SQLSelectLimit, "18446744073709551615"},
 	{ScopeGlobal, "ndb_show_foreign_key_mock_tables", ""},
@@ -606,7 +612,6 @@ var defaultSysVars = []*SysVar{
 	{ScopeGlobal, "sync_relay_log_info", "10000"},
 	{ScopeGlobal | ScopeSession, "optimizer_trace_limit", "1"},
 	{ScopeNone, "innodb_ft_max_token_size", "84"},
-	{ScopeGlobal, "validate_password_length", "8"},
 	{ScopeGlobal, "ndb_log_binlog_index", ""},
 	{ScopeGlobal, "innodb_api_bk_commit_interval", "5"},
 	{ScopeNone, "innodb_undo_directory", "."},
@@ -815,10 +820,20 @@ const (
 	BlockEncryptionMode = "block_encryption_mode"
 	// WaitTimeout is the name for 'wait_timeout' system variable.
 	WaitTimeout = "wait_timeout"
-	// ValidatePasswordNumberCount is the name of 'validate_password_number_count' system variable.
-	ValidatePasswordNumberCount = "validate_password_number_count"
+	// ValidatePasswordCheckUserName is the name of 'validate_password_check_user_name' system variable
+	ValidatePasswordCheckUserName = "validate_password_check_user_name"
+	// ValidatePasswordDictionaryFile is the name of 'validate_password_dictionary_file' system variable
+	ValidatePasswordDictionaryFile = "validate_password_dictionary_file"
 	// ValidatePasswordLength is the name of 'validate_password_length' system variable.
 	ValidatePasswordLength = "validate_password_length"
+	// ValidatePasswordMixedCaseCount is the name of 'validate_password_mixed_case_count' system variable
+	ValidatePasswordMixedCaseCount = "validate_password_mixed_case_count"
+	// ValidatePasswordNumberCount is the name of 'validate_password_number_count' system variable.
+	ValidatePasswordNumberCount = "validate_password_number_count"
+	// ValidatePasswordPolicy is the name of 'validate_password_policy' system variable
+	ValidatePasswordPolicy = "validate_password_policy"
+	// ValidatePasswordSpecialCharCount is the name of 'validate_password_special_char_count' system variable
+	ValidatePasswordSpecialCharCount = "validate_password_special_char_count"
 	// PluginDir is the name of 'plugin_dir' system variable.
 	PluginDir = "plugin_dir"
 	// PluginLoad is the name of 'plugin_load' system variable.
@@ -835,8 +850,6 @@ const (
 	BinlogOrderCommits = "binlog_order_commits"
 	// MasterVerifyChecksum is the name for 'master_verify_checksum' system variable.
 	MasterVerifyChecksum = "master_verify_checksum"
-	// ValidatePasswordCheckUserName is the name for 'validate_password_check_user_name' system variable.
-	ValidatePasswordCheckUserName = "validate_password_check_user_name"
 	// SuperReadOnly is the name for 'super_read_only' system variable.
 	SuperReadOnly = "super_read_only"
 	// SQLNotes is the name for 'sql_notes' system variable.
diff --git a/sessionctx/variable/varsutil.go b/sessionctx/variable/varsutil.go
index ae244d93face2..e7d2feeac5375 100644
--- a/sessionctx/variable/varsutil.go
+++ b/sessionctx/variable/varsutil.go
@@ -347,8 +347,17 @@ func ValidateSetSystemVar(vars *SessionVars, name string, value string) (string,
 		}
 		_, err := parseTimeZone(value)
 		return value, err
-	case ValidatePasswordLength, ValidatePasswordNumberCount:
-		return checkUInt64SystemVar(name, value, 0, math.MaxUint64, vars)
+	case ValidatePasswordLength, ValidatePasswordMixedCaseCount, ValidatePasswordNumberCount, ValidatePasswordSpecialCharCount:
+		return checkUInt64SystemVar(name, value, 0, 100, vars)
+	case ValidatePasswordPolicy:
+		if strings.EqualFold(value, "LOW") || value == "0" {
+			return "0", nil
+		} else if strings.EqualFold(value, "MEDIUM") || value == "1" {
+			return "1", nil
+		} else if strings.EqualFold(value, "STRONG") || value == "2" {
+			return "2", nil
+		}
+		return value, ErrWrongValueForVar.GenWithStackByArgs(name, value)
 	case WarningCount, ErrorCount:
 		return value, ErrReadOnly.GenWithStackByArgs(name)
 	case EnforceGtidConsistency: