diff --git a/README.md b/README.md
index f5e620d..d79d2cf 100644
--- a/README.md
+++ b/README.md
@@ -5,13 +5,13 @@ CodiMD 的命令列工具 - 讓你可以透過終端機管理 CodiMD 協作筆
 ## 安裝
 
 ```bash
-# 從 Git 仓库安裝
-pip install git+http://192.168.42.124:31337/timmy/cli-anything-codimd.git
+# 從 Git 仓库安裝（含管理員功能）
+pip install -e ".[admin]" git+http://192.168.42.124:31337/timmy/cli-anything-codimd.git
 
 # 或是複製後手動安裝
 git clone http://192.168.42.124:31337/timmy/cli-anything-codimd.git
 cd cli-anything-codimd/agent-harness
-pip install -e .
+pip install -e ".[admin]"
 ```
 
 ## 使用方法
@@ -75,12 +75,13 @@ cli-anything-codimd repl
 | `revision get <id> <time>` | 取得特定時間的版本 |
 
 ### 管理員指令
-需要直接存取 CodiMD 資料庫。
+需要直接存取 CodiMD 資料庫，需要安裝額外依賴：`pip install -e ".[admin]"`
 
 | 指令 | 說明 |
 |------|------|
 | `admin list-users` | 列出所有使用者 |
 | `admin user-notes <id>` | 列出使用者的筆記 |
+| `admin reset-password` | 重設使用者密碼 |
 
 #### 資料庫使用範例
 
@@ -98,6 +99,18 @@ cli-anything-codimd admin list-users --db-type mysql \
 
 # 查看特定使用者的筆記
 cli-anything-codimd admin user-notes <user-id> --db-path ./db.sqlite
+
+# 重設使用者密碼（透過 Email）
+cli-anything-codimd admin reset-password --email user@example.com \
+  --db-path ./db.sqlite
+
+# 重設使用者密碼（透過 User ID）
+cli-anything-codimd admin reset-password --user-id <user-id> \
+  --db-path ./db.sqlite
+
+# 重設密碼（PostgreSQL）
+cli-anything-codimd admin reset-password --email user@example.com \
+  --db-type postgresql --db-host localhost --db-name codimd --db-user postgres
 ```
 
 ### 設定指令
diff --git a/cli_anything/codimd/codimd_cli.py b/cli_anything/codimd/codimd_cli.py
index ca23cd3..6767fec 100644
--- a/cli_anything/codimd/codimd_cli.py
+++ b/cli_anything/codimd/codimd_cli.py
@@ -708,6 +708,76 @@ def admin_user_notes(user_id, db_path):
                 click.echo(f"  {note_id} | {title[:50]} | [{permission}]")
 
 
+@admin.command("reset-password")
+@click.option("--db-type", type=click.Choice(["sqlite", "postgresql", "mysql"]), default="sqlite", help="Database type")
+@click.option("--db-path", type=Path, help="SQLite database path")
+@click.option("--db-host", help="Database host (for PostgreSQL/MySQL)")
+@click.option("--db-name", help="Database name (for PostgreSQL/MySQL)")
+@click.option("--db-user", help="Database user (for PostgreSQL/MySQL)")
+@click.option("--db-password", help="Database password (for PostgreSQL/MySQL)")
+@click.option("--db-port", type=int, default=5432, help="Database port")
+@click.option("--email", help="User email to reset password for")
+@click.option("--user-id", help="User ID to reset password for")
+@click.option("--password", help="New password (will prompt if not provided)")
+@click.confirmation_option(prompt="Are you sure you want to reset this user's password?")
+@handle_error
+def admin_reset_password(db_type, db_path, db_host, db_name, db_user, db_password, db_port, email, user_id, password):
+    """Reset a user's password."""
+    from cli_anything.codimd.core import CodiMDDatabase
+
+    if not email and not user_id:
+        raise ValueError("Either --email or --user-id must be specified")
+
+    if not password:
+        password = click.prompt("New password", hide_input=True, confirmation_prompt=True)
+
+    if db_type == "sqlite":
+        if not db_path:
+            # Try default paths
+            default_paths = [
+                "./codimd/db.sqlite",
+                "./db.sqlite",
+                "/var/lib/codimd/db.sqlite"
+            ]
+            for path in default_paths:
+                if Path(path).exists():
+                    db_path = path
+                    break
+            if not db_path:
+                raise ValueError("SQLite database path not found. Use --db-path")
+
+        if user_id:
+            CodiMDDatabase.reset_password_sqlite_by_id(str(db_path), user_id, password)
+            click.echo(f"Password reset for user ID: {user_id}")
+        else:
+            CodiMDDatabase.reset_password_sqlite(str(db_path), email, password)
+            click.echo(f"Password reset for: {email}")
+
+    elif db_type == "postgresql":
+        if not all([db_host, db_name, db_user]):
+            raise ValueError("--db-host, --db-name, and --db-user are required for PostgreSQL")
+        if not db_password:
+            db_password = click.prompt("Database password", hide_input=True)
+
+        CodiMDDatabase.reset_password_postgresql(
+            db_host, db_name, db_user, db_password, db_port, email, password
+        )
+        click.echo(f"Password reset for: {email}")
+
+    elif db_type == "mysql":
+        if not all([db_host, db_name, db_user]):
+            raise ValueError("--db-host, --db-name, and --db-user are required for MySQL")
+        if not db_password:
+            db_password = click.prompt("Database password", hide_input=True)
+
+        CodiMDDatabase.reset_password_mysql(
+            db_host, db_name, db_user, db_password, db_port, email, password
+        )
+        click.echo(f"Password reset for: {email}")
+
+    click.echo("✓ Password has been updated. The user can now log in with the new password.")
+
+
 # REPL mode
 @cli.command("repl")
 @handle_error
diff --git a/cli_anything/codimd/core/db.py b/cli_anything/codimd/core/db.py
index ca35557..938f7b5 100644
--- a/cli_anything/codimd/core/db.py
+++ b/cli_anything/codimd/core/db.py
@@ -9,6 +9,45 @@ from typing import List, Dict, Any, Optional
 from pathlib import Path
 
 
+class PasswordHasher:
+    """Password hashing compatible with CodiMD (scrypt-kdf)."""
+
+    @staticmethod
+    def hash_password(password: str) -> str:
+        """Hash password using scrypt (compatible with CodiMD).
+
+        CodiMD uses scrypt-kdf with default parameters (N=16384, r=8, p=1).
+        Returns hex-encoded hash that CodiMD can verify.
+        """
+        try:
+            import hashlib
+            import scrypt
+            import os
+            # Generate random salt (16 bytes)
+            salt = os.urandom(16)
+            # Scrypt parameters matching CodiMD defaults
+            N = 16384
+            r = 8
+            p = 1
+            # Derive key (64 bytes output)
+            derived_key = scrypt.hash(
+                password.encode(),
+                salt,
+                N,
+                r,
+                p,
+                64  # output length in bytes
+            )
+            # Return hex-encoded salt + hash (CodiMD format)
+            return salt.hex() + derived_key.hex()
+        except ImportError:
+            raise ImportError(
+                "scrypt required for password operations. "
+                "Install with: pip install scrypt\n"
+                "Or install with: pip install cli-anything-codimd[admin]"
+            )
+
+
 class CodiMDDatabase:
     """Direct database access for CodiMD."""
 
@@ -148,3 +187,147 @@ class CodiMDDatabase:
         notes = [dict(row) for row in cursor.fetchall()]
         conn.close()
         return notes
+
+    @staticmethod
+    def reset_password_sqlite(db_path: str, email: str, new_password: str) -> bool:
+        """Reset user password in SQLite database."""
+        try:
+            import sqlite3
+        except ImportError:
+            raise ImportError("sqlite3 required for SQLite access")
+
+        # Hash the new password
+        hashed_password = PasswordHasher.hash_password(new_password)
+
+        conn = sqlite3.connect(db_path)
+        cursor = conn.cursor()
+
+        # Check if user exists by email
+        cursor.execute("SELECT id, email FROM Users WHERE email = ?", (email,))
+        user = cursor.fetchone()
+
+        if not user:
+            conn.close()
+            raise ValueError(f"User not found: {email}")
+
+        user_id, user_email = user
+
+        # Update password
+        cursor.execute(
+            'UPDATE Users SET password = ? WHERE email = ?',
+            (hashed_password, email)
+        )
+
+        conn.commit()
+        conn.close()
+        return True
+
+    @staticmethod
+    def reset_password_sqlite_by_id(db_path: str, user_id: str, new_password: str) -> bool:
+        """Reset user password in SQLite database by user ID."""
+        try:
+            import sqlite3
+        except ImportError:
+            raise ImportError("sqlite3 required for SQLite access")
+
+        # Hash the new password
+        hashed_password = PasswordHasher.hash_password(new_password)
+
+        conn = sqlite3.connect(db_path)
+        cursor = conn.cursor()
+
+        # Check if user exists
+        cursor.execute("SELECT id, email FROM Users WHERE id = ?", (user_id,))
+        user = cursor.fetchone()
+
+        if not user:
+            conn.close()
+            raise ValueError(f"User not found: {user_id}")
+
+        # Update password
+        cursor.execute(
+            'UPDATE Users SET password = ? WHERE id = ?',
+            (hashed_password, user_id)
+        )
+
+        conn.commit()
+        conn.close()
+        return True
+
+    @staticmethod
+    def reset_password_postgresql(host: str, database: str, user: str, password: str,
+                                  port: int, target_email: str, new_password: str) -> bool:
+        """Reset user password in PostgreSQL database."""
+        try:
+            import psycopg2
+        except ImportError:
+            raise ImportError("psycopg2 required for PostgreSQL access")
+
+        # Hash the new password
+        hashed_password = PasswordHasher.hash_password(new_password)
+
+        conn = psycopg2.connect(
+            host=host,
+            database=database,
+            user=user,
+            password=password,
+            port=port
+        )
+        cursor = conn.cursor()
+
+        # Check if user exists
+        cursor.execute('SELECT id, email FROM "Users" WHERE email = %s', (target_email,))
+        row = cursor.fetchone()
+
+        if not row:
+            conn.close()
+            raise ValueError(f"User not found: {target_email}")
+
+        # Update password
+        cursor.execute(
+            'UPDATE "Users" SET password = %s WHERE email = %s',
+            (hashed_password, target_email)
+        )
+
+        conn.commit()
+        conn.close()
+        return True
+
+    @staticmethod
+    def reset_password_mysql(host: str, database: str, user: str, password: str,
+                            port: int, target_email: str, new_password: str) -> bool:
+        """Reset user password in MySQL database."""
+        try:
+            import mysql.connector
+        except ImportError:
+            raise ImportError("mysql-connector-python required for MySQL access")
+
+        # Hash the new password
+        hashed_password = PasswordHasher.hash_password(new_password)
+
+        conn = mysql.connector.connect(
+            host=host,
+            database=database,
+            user=user,
+            password=password,
+            port=port
+        )
+        cursor = conn.cursor()
+
+        # Check if user exists
+        cursor.execute('SELECT id, email FROM Users WHERE email = %s', (target_email,))
+        row = cursor.fetchone()
+
+        if not row:
+            conn.close()
+            raise ValueError(f"User not found: {target_email}")
+
+        # Update password
+        cursor.execute(
+            'UPDATE Users SET password = %s WHERE email = %s',
+            (hashed_password, target_email)
+        )
+
+        conn.commit()
+        conn.close()
+        return True
diff --git a/setup.py b/setup.py
index aa430e9..c73130f 100644
--- a/setup.py
+++ b/setup.py
@@ -31,6 +31,9 @@ setup(
             "requests-mock>=1.9.0",
             "pytest-subprocess>=1.5.0",
         ],
+        "admin": [
+            "scrypt>=0.8.0",
+        ],
     },
     entry_points={
         "console_scripts": [