diff --git a/deps/oblib/src/lib/charset/ob_charset.h b/deps/oblib/src/lib/charset/ob_charset.h
index 4e9acbafe507ba4617607dce44e2c26f0597e1ae..dd3062b851f7f2fcdb19dcb0175d86028bfdbd7a 100644
--- a/deps/oblib/src/lib/charset/ob_charset.h
+++ b/deps/oblib/src/lib/charset/ob_charset.h
@@ -277,7 +277,7 @@ public:
     return result;
   }
   template <typename foreach_char_func>
-  static int foreach_char(common::ObString& str, common::ObCollationType collation_type, foreach_char_func& func)
+  static int foreach_char(const common::ObString &str, common::ObCollationType collation_type, foreach_char_func &func)
   {
     int ret = common::OB_SUCCESS;
     int32_t wchar = 0;
diff --git a/deps/oblib/src/lib/ob_name_def.h b/deps/oblib/src/lib/ob_name_def.h
index 98ea1066360818cf0a768fdf85a64dff2831c73a..5f4773454ff10ec6ce6ece82439aae132c3d0bf5 100644
--- a/deps/oblib/src/lib/ob_name_def.h
+++ b/deps/oblib/src/lib/ob_name_def.h
@@ -336,6 +336,7 @@
 #define N_OPERATOR_MONITOR_INFO "op_info"
 #define N_PLAN_MONITOR_INFO "plan_info"
 #define N_ANY_VAL "any_value"
+#define N_VALIDATE_PASSWORD_STRENGTH "validate_password_strength"
 // common comparison operator
 #define N_LESS_THAN "<"
 #define N_GREATER_THAN ">"
diff --git a/src/sql/CMakeLists.txt b/src/sql/CMakeLists.txt
index 4f037d0408761a44309ba217eb81e495ac1c14f1..9255a4c089c7aa04100bce348336dfef5d75a40d 100644
--- a/src/sql/CMakeLists.txt
+++ b/src/sql/CMakeLists.txt
@@ -464,6 +464,8 @@ ob_set_subtarget(ob_sql engine
   engine/expr/ob_expr_calc_urowid.cpp
   engine/expr/ob_expr_cardinality.cpp
   engine/expr/ob_expr_coll_pred.cpp
+  engine/expr/ob_expr_validate_password_strength.cpp
+  engine/expr/ob_expr_validate_password_strength.h
   engine/expr/ob_expr_benchmark.cpp
   engine/expr/ob_expr_benchmark.h
   engine/join/ob_basic_nested_loop_join.cpp
diff --git a/src/sql/engine/expr/ob_expr_eval_functions.cpp b/src/sql/engine/expr/ob_expr_eval_functions.cpp
index fa411a003ea479d568aa6e3c7fa86914b494111d..aae88e129fee1f43bc14fb4c080e7852d1988a08 100644
--- a/src/sql/engine/expr/ob_expr_eval_functions.cpp
+++ b/src/sql/engine/expr/ob_expr_eval_functions.cpp
@@ -187,6 +187,7 @@
 #include "ob_expr_degrees.h"
 #include "ob_expr_weight_string.h"
 #include "ob_expr_any_value.h"
+#include "ob_expr_validate_password_strength.h"
 #include "ob_expr_benchmark.h"
 
 namespace oceanbase {
@@ -704,7 +705,7 @@ static ObExpr::EvalFunc g_expr_eval_functions[] = {
     NULL,                                     /* 440 */
     ObExprTimestamp::calc_timestamp1,         /* 441 */
     ObExprTimestamp::calc_timestamp2,         /* 442 */
-    NULL,                                     /* 443 */
+    ObExprValidatePasswordStrength::eval_password_strength, /* 443 */
     NULL,                                     /* 444 */
     NULL,                                     /* 445 */
     NULL,                                     /* 446 */
diff --git a/src/sql/engine/expr/ob_expr_operator_factory.cpp b/src/sql/engine/expr/ob_expr_operator_factory.cpp
index 67d3fec59007b7140ec4186db5770aacaec47241..3087eb8c2e04c12397a4fbb66b40fa7543b6b160 100644
--- a/src/sql/engine/expr/ob_expr_operator_factory.cpp
+++ b/src/sql/engine/expr/ob_expr_operator_factory.cpp
@@ -271,6 +271,7 @@
 #include "sql/engine/expr/ob_expr_degrees.h"
 #include "sql/engine/expr/ob_expr_weight_string.h"
 #include "sql/engine/expr/ob_expr_any_value.h"
+#include "sql/engine/expr/ob_expr_validate_password_strength.h"
 #include "sql/engine/expr/ob_expr_benchmark.h"
 
 using namespace oceanbase::common;
@@ -683,6 +684,7 @@ void ObExprOperatorFactory::register_expr_operators()
   REG_OP(ObExprTimeFormat);
   REG_OP(ObExprTimestamp);
   REG_OP(ObExprDegrees);
+  REG_OP(ObExprValidatePasswordStrength);
   REG_OP(ObExprWeightString);
   REG_OP(ObExprBenchmark);
   REG_OP(ObExprDay);
diff --git a/src/sql/engine/expr/ob_expr_validate_password_strength.cpp b/src/sql/engine/expr/ob_expr_validate_password_strength.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..19f8f9e84a2455fd3e05a234860030a6df344f2d
--- /dev/null
+++ b/src/sql/engine/expr/ob_expr_validate_password_strength.cpp
@@ -0,0 +1,211 @@
+// Copyright (c) 2021 Alibaba Inc. All Rights Reserved.
+// Author:
+//   renqing <sean.yyj@antgroup.com>
+
+#define USING_LOG_PREFIX SQL_ENG
+
+#include "ob_expr_validate_password_strength.h"
+
+#include "sql/session/ob_sql_session_info.h"
+#include "sql/engine/ob_exec_context.h"
+
+using namespace oceanbase::common;
+using namespace oceanbase::sql;
+namespace oceanbase {
+namespace sql {
+
+const ObValidatePasswordFunc ObExprValidatePasswordStrength::validate_funcs_[STRENGTH_MAX] = {
+    NULL,  // STRENGTH_WEAK is default strength, need no validation
+    ObExprValidatePasswordStrength::validate_password_lessweak,
+    ObExprValidatePasswordStrength::validate_password_low,
+    ObExprValidatePasswordStrength::validate_password_medium,
+    ObExprValidatePasswordStrength::validate_password_strong,
+};
+
+ObExprValidatePasswordStrength::ObExprValidatePasswordStrength(ObIAllocator &alloc)
+    : ObFuncExprOperator(
+          alloc, T_FUN_SYS_VALIDATE_PASSWORD_STRENGTH, N_VALIDATE_PASSWORD_STRENGTH, 1, NOT_ROW_DIMENSION)
+{}
+
+ObExprValidatePasswordStrength::~ObExprValidatePasswordStrength()
+{}
+
+int ObExprValidatePasswordStrength::calc_result_type1(
+    ObExprResType &type, ObExprResType &type1, ObExprTypeCtx &type_ctx) const
+{
+  int ret = OB_SUCCESS;
+  UNUSED(type_ctx);
+  type.set_int();
+  type.set_scale(common::ObAccuracy::DDL_DEFAULT_ACCURACY[common::ObIntType].scale_);
+  type.set_precision(common::ObAccuracy::DDL_DEFAULT_ACCURACY[common::ObIntType].precision_);
+  type1.set_calc_type(common::ObVarcharType);
+  ObExprOperator::calc_result_flag1(type, type1);
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::calc_result1(ObObj &result, const ObObj &obj1, ObExprCtx &expr_ctx) const
+{
+  int ret = OB_SUCCESS;
+  if (OB_ISNULL(expr_ctx.my_session_) || OB_ISNULL(expr_ctx.calc_buf_)) {
+    ret = OB_INVALID_ARGUMENT;
+    LOG_WARN("Invalid argument", KP(expr_ctx.my_session_), KP(expr_ctx.calc_buf_), K(ret));
+  } else if (obj1.is_null()) {
+    result.set_null();
+  } else {
+    ObString password;
+    int strength = 0;
+    if (OB_FAIL(ObCharset::charset_convert(*expr_ctx.calc_buf_,
+            obj1.get_string(),
+            obj1.get_collation_type(),
+            ObCharset::get_system_collation(),
+            password))) {
+      LOG_WARN("fail to convert password to sys collation", K(obj1), K(ret));
+    } else if (OB_FAIL(calc_password_strength(password, *expr_ctx.my_session_, strength))) {
+      LOG_WARN("fail to calc password strength", K(password), K(ret));
+    } else {
+      result.set_int(strength);
+    }
+  }
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::cg_expr(ObExprCGCtx &op_cg_ctx, const ObRawExpr &raw_expr, ObExpr &rt_expr) const
+{
+  int ret = OB_SUCCESS;
+  UNUSED(op_cg_ctx);
+  UNUSED(raw_expr);
+  rt_expr.eval_func_ = eval_password_strength;
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::eval_password_strength(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &res_datum)
+{
+  int ret = OB_SUCCESS;
+  ObDatum *pwd_param = NULL;
+  ObCollationType c_src = ObCollationType::CS_TYPE_INVALID;
+  ObString password_orig;
+  ObString password;
+  int strength = 0;
+
+  const ObBasicSessionInfo *session = ctx.exec_ctx_.get_my_session();
+  if (OB_ISNULL(session)) {
+    LOG_WARN("session is null", K(ret));
+  } else if (OB_FAIL(expr.args_[0]->eval(ctx, pwd_param))) {
+    LOG_WARN("eval arg failed", K(ret));
+  } else if (pwd_param->is_null()) {
+    res_datum.set_null();
+  } else if (FALSE_IT(password_orig = pwd_param->get_string())) {
+  } else if (FALSE_IT(c_src = expr.args_[0]->obj_meta_.get_collation_type())) {
+  } else if (OB_FAIL(ObCharset::charset_convert(
+                 ctx.exec_ctx_.get_allocator(), password_orig, c_src, ObCharset::get_system_collation(), password))) {
+    LOG_WARN("fail to convert password to sys collation", K(password_orig), K(c_src), K(ret));
+  } else if (OB_FAIL(calc_password_strength(password, *session, strength))) {
+    LOG_WARN("fail to calc password strength", K(password), K(ret));
+  } else {
+    res_datum.set_int(strength);
+  }
+
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::calc_password_strength(
+    const ObString &password, const ObBasicSessionInfo &session, int &strength)
+{
+  int ret = OB_SUCCESS;
+  bool passed = true;
+  strength = 0;
+  for (int i = STRENGTH_LESSWEAK; OB_SUCC(ret) && passed && i < STRENGTH_MAX; ++i) {
+    if (OB_FAIL(validate_funcs_[i](password, session, passed))) {
+      LOG_WARN("failed to validate", K(password), K(i), K(ret));
+    } else if (passed) {
+      strength = i * PASSWORD_STRENGTH_MULTIPLIER;
+    }
+  }
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::validate_password_lessweak(
+    const ObString &password, const ObBasicSessionInfo &session, bool &passed)
+{
+  int ret = OB_SUCCESS;
+  int64_t check_user_name = 0;
+  passed = false;
+  if (OB_FAIL(session.get_sys_variable(share::SYS_VAR_VALIDATE_PASSWORD_CHECK_USER_NAME, check_user_name))) {
+    LOG_WARN("fail to get validate_password_length", K(ret));
+  } else {
+    passed = password.length() >= VALID_PASSWORD_LENGTH_MIN &&
+             (!check_user_name && !ObCharset::case_insensitive_equal(password, session.get_user_name()));
+  }
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::validate_password_low(
+    const ObString &password, const ObBasicSessionInfo &session, bool &passed)
+{
+  int ret = OB_SUCCESS;
+  uint64_t valid_pw_len = 0;
+  passed = false;
+  if (OB_FAIL(session.get_sys_variable(share::SYS_VAR_VALIDATE_PASSWORD_LENGTH, valid_pw_len))) {
+    LOG_WARN("fail to get validate_password_length", K(ret));
+  } else {
+    passed = password.length() >= valid_pw_len;
+  }
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::validate_password_medium(
+    const ObString &password, const ObBasicSessionInfo &session, bool &passed)
+{
+  int ret = OB_SUCCESS;
+  uint64_t valid_mix_case_count = 0;
+  uint64_t valid_number_count = 0;
+  uint64_t valid_special_count = 0;
+  uint64_t lower_count = 0;
+  uint64_t upper_count = 0;
+  uint64_t digit_count = 0;
+  uint64_t special_count = 0;
+  passed = false;
+  if (OB_FAIL(session.get_sys_variable(share::SYS_VAR_VALIDATE_PASSWORD_MIXED_CASE_COUNT, valid_mix_case_count))) {
+    LOG_WARN("fail to get validate_password_mixed_case_count", K(ret));
+  } else if (OB_FAIL(session.get_sys_variable(share::SYS_VAR_VALIDATE_PASSWORD_NUMBER_COUNT, valid_number_count))) {
+    LOG_WARN("fail to get validate_password_number_count", K(ret));
+  } else if (OB_FAIL(
+                 session.get_sys_variable(share::SYS_VAR_VALIDATE_PASSWORD_SPECIAL_CHAR_COUNT, valid_special_count))) {
+    LOG_WARN("fail to get validate_password_special_char_count", K(ret));
+  } else {
+    auto handle_char_func = [&lower_count, &upper_count, &digit_count, &special_count](ObString, int wchar) -> int {
+      int ret = OB_SUCCESS;
+      if (islower(wchar)) {
+        lower_count++;
+      } else if (isupper(wchar)) {
+        upper_count++;
+      } else if (isdigit(wchar)) {
+        digit_count++;
+      } else {
+        special_count++;
+      }
+      return ret;
+    };
+    OZ(ObCharsetUtils::foreach_char(password, ObCharset::get_system_collation(), handle_char_func));
+  }
+  if (OB_SUCC(ret)) {
+    passed = lower_count >= valid_mix_case_count && upper_count >= valid_mix_case_count &&
+             digit_count >= valid_number_count && special_count >= valid_special_count;
+  }
+  return ret;
+}
+
+int ObExprValidatePasswordStrength::validate_password_strong(
+    const ObString &password, const ObBasicSessionInfo &session, bool &passed)
+{
+  int ret = OB_SUCCESS;
+  UNUSED(password);
+  UNUSED(session);
+  // Check if the password matches the words in the dictionary file. The dictionary file is not
+  // supported in OB yet, so this validation always passed
+  passed = true;
+  return ret;
+}
+
+}  // namespace sql
+}  // namespace oceanbase
diff --git a/src/sql/engine/expr/ob_expr_validate_password_strength.h b/src/sql/engine/expr/ob_expr_validate_password_strength.h
new file mode 100644
index 0000000000000000000000000000000000000000..07c358e523d41781bbaaa82ba8664ee9194e0e45
--- /dev/null
+++ b/src/sql/engine/expr/ob_expr_validate_password_strength.h
@@ -0,0 +1,50 @@
+// Copyright (c) 2021 Alibaba Inc. All Rights Reserved.
+// Author:
+//   renqing <sean.yyj@antgroup.com>
+
+#ifndef SRC_SQL_ENGINE_EXPR_OB_EXPR_VALIDATE_PASSWORD_STRENGTH_H_
+#define SRC_SQL_ENGINE_EXPR_OB_EXPR_VALIDATE_PASSWORD_STRENGTH_H_
+
+#include "sql/engine/expr/ob_expr_operator.h"
+
+namespace oceanbase {
+namespace sql {
+
+typedef int (*ObValidatePasswordFunc)(
+    const common::ObString &password, const ObBasicSessionInfo &session, bool &passed);
+class ObExprValidatePasswordStrength : public ObFuncExprOperator {
+public:
+  enum PasswordStrength {
+    STRENGTH_WEAK = 0,
+    STRENGTH_LESSWEAK,
+    STRENGTH_LOW,
+    STRENGTH_MEDIUM,
+    STRENGTH_STRONG,
+    STRENGTH_MAX,
+  };
+  explicit ObExprValidatePasswordStrength(common::ObIAllocator &alloc);
+  virtual ~ObExprValidatePasswordStrength();
+  virtual int calc_result_type1(ObExprResType &type, ObExprResType &type1, common::ObExprTypeCtx &type_ctx) const;
+  virtual int calc_result1(common::ObObj &result, const common::ObObj &obj1, common::ObExprCtx &expr_ctx) const;
+  virtual int cg_expr(ObExprCGCtx &op_cg_ctx, const ObRawExpr &raw_expr, ObExpr &rt_expr) const override;
+  static int eval_password_strength(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &res_datum);
+
+private:
+  static int calc_password_strength(const common::ObString &password, const ObBasicSessionInfo &session, int &strength);
+  static int validate_password_lessweak(
+      const common::ObString &password, const ObBasicSessionInfo &session, bool &passed);
+  static int validate_password_low(const common::ObString &password, const ObBasicSessionInfo &session, bool &passed);
+  static int validate_password_medium(
+      const common::ObString &password, const ObBasicSessionInfo &session, bool &passed);
+  static int validate_password_strong(
+      const common::ObString &password, const ObBasicSessionInfo &session, bool &passed);
+  static const int64_t VALID_PASSWORD_LENGTH_MIN = 4;
+  static const int64_t PASSWORD_STRENGTH_MULTIPLIER = 25;
+  static const ObValidatePasswordFunc validate_funcs_[STRENGTH_MAX];
+  // disallow copy
+  DISALLOW_COPY_AND_ASSIGN(ObExprValidatePasswordStrength);
+};
+}  // namespace sql
+}  // namespace oceanbase
+
+#endif /* SRC_SQL_ENGINE_EXPR_OB_EXPR_VALIDATE_PASSWORD_STRENGTH_H_ */
diff --git a/src/sql/parser/ob_item_type.h b/src/sql/parser/ob_item_type.h
index f41a41437516e9262e89718e1b9645638f09c445..567c6f9423bf1e4c5880585d29f7bec58bf069b3 100644
--- a/src/sql/parser/ob_item_type.h
+++ b/src/sql/parser/ob_item_type.h
@@ -428,6 +428,7 @@ typedef enum ObItemType {
   T_FUN_SYS_PI = 713,
   T_FUN_SYS_ANY_VALUE = 714,
   T_FUN_SYS_DEGREES = 715,
+  T_FUN_SYS_VALIDATE_PASSWORD_STRENGTH = 716,
   T_FUN_SYS_BENCHMARK = 720,
   T_FUN_SYS_EXPORT_SET = 721,