Unlock your Mac with Apple Watch
If you have a Mac (mid-2013 or later) with macOS Sierra (Apple Watch Series 1 and 2) or macOS High Sierra or later (Apple Watch Series 3 or later), your Apple Watch can instantly unlock your Mac when it wakes from sleep. You need to be signed in to iCloud using the same Apple ID on both your Mac and Apple Watch.
Tip: To find out how old your Mac is, click the Apple menu in the top-left corner of your computer screen, then choose About This Mac. The year your Mac was made is listed next to the model—for example, “MacBook Pro (Retina, 13-inch, Mid 2014).”
Turn on Auto Unlock
On your Mac, choose Apple menu > System Preferences.
Click Security & Privacy, then click General.
Select the “Allow Apple Watch to unlock your Mac” checkbox.
If you don’t have two-factor authentication turned on for your Apple ID, follow the onscreen instructions, then try selecting the checkbox again. See the Apple Support article Two-factor authentication for Apple ID.
Your Mac must also have Wi-Fi and Bluetooth turned on.
Unlock your Mac
While wearing your watch, just wake up your Mac—no need to type in your password.
Tip: Make sure your Apple Watch is on your wrist and unlocked.