Step 1: Apple -> System Preferences -> click mysql at the bottom, close the mysql service
Step 2: Enter the terminal input (cd /usr/local/mysql/bin/) and press Enter
Type (sudo su) and press Enter to gain administrator privileges
Enter (./mysqld_safe --skip-grant-tables &) and press Enter to disable the mysql authentication function, mysql will automatically restart, and the mysql status in the preferences will change to running
Step 3: Open a new command window (note!!!!!!)
Execute cd /usr/local/mysql/bin; press Enter
(./mysql) Enter
Enter the command (flush privileges;) Don't forget to lose the semicolon
Enter the command (set password for 'root'@'localhost' = password('root');) root in password('root') is the new password, set it yourself, don't forget to enter the semicolon
So far, the password has been changed successfully and you can log in normally.