方法1: By Access Single-User mode.

Use your left hand to hold down the  'Command' + 'S'

localhost:/ root#

/sbin/fsck -fy
/sbin/mount -rw /

# Skip this step if you’re running 10.6 Snow Leopard or earlier.

launchctl load /System/Library/LaunchDaemons/com.apple.opendirectoryd.plist

# A list of all of the accounts on your computer

ls /Users

# Reset the password

dscl . passwd /Users/<username> <new-pw>

# reboot

reboot

方法2: Boot into Recovery Partition

down the ‘command’ + ‘r’ keys on the keyboard

Go to the Utilites menu and select Terminal

At the prompt type ‘resetpassword’