摘自 stackoverflow回答

Here is the procedure to reset password of root user.

1) Stop mysql (Kill mysql process or run following command)

sudo /usr/local/mysql/support-files/mysql.server stop

2) Start it in safe mode

sudo mysqld_safe --skip-grant-tables

3) Open another terminal and run the following command (Keep last terminal open)

mysql -u root

4) Run the following command with suitable new password on the mysql console

mysql > UPDATE mysql.user SET Password=PASSWORD(‘password‘) WHERE User=‘root‘;

5) mysql > FLUSH PRIVILEGES;

6) Quit from both terminals and open new terminal and connect to mysql with root user and new password

mysql -uroot -p