Switch quickly between users on Mac
If your Mac has multiple users, an administrator can turn on fast user switching, which allows you to quickly switch between accounts when more than one user is logged in at the same time.
Show fast user switching in the menu bar
On your Mac, choose Apple menu
in the sidebar. (You may need to scroll down.)Go to Fast User Switching on the right, click the pop-up menu next to Show in Menu Bar, then choose an option.
Show fast user switching in Control Center
On your Mac, choose Apple menu
Go to Fast User Switching on the right, then turn on Show in Control Center.
Switch accounts using the menu bar
On your Mac, click the fast user switching menu in the menu bar, then choose your user name or icon.
The fast user switching menu is in the upper-right corner of the screen and looks like a user icon or shows the name of the current user, depending on the setting in Control Center settings.
Enter your password, then press Return.
Switch accounts using Touch ID
When two or more users are logged in at the same time, you can quickly switch between users using Touch ID. To set up Touch ID, see Use Touch ID.
If your Mac has a Touch Bar: Place your finger on Touch ID until “Press Touch ID to switch to [your name]” appears in the Touch Bar, then press Touch ID until it clicks.
If your Mac or Magic Keyboard has Touch ID only (no Touch Bar): Press Touch ID until it clicks.
Switch accounts using Control Center
On your Mac, click Control Center in the menu bar, click the user icon or name, then choose your user name.
If the fast user switching icon doesn’t appear in Control Center, choose Apple menu 
in the sidebar, then turn on Show in Control Center on the right. (You may need to scroll down.)