Unlock AppleWatch
You can unlock AppleWatch manually, by entering the passcode, or set it to unlock automatically when you unlock your iPhone.
Enter the passcode: Wake AppleWatch, then enter the watch passcode.
Unlock AppleWatch when you unlock your iPhone: Open the AppleWatch app on your iPhone, tap My Watch, tap Passcode, then turn on Unlock with iPhone.
Your iPhone must be within normal Bluetooth range (about 33 feet or 10 meters) of your AppleWatch to unlock it. If Bluetooth is off on AppleWatch, enter the passcode on your watch to unlock it.
Tip: Your AppleWatch passcode can be different from your iPhone passcode—in fact, it’s better to use different passcodes.
Change your passcode
You can change the passcode you created when you first set up your AppleWatch by following these steps:
Open the Settings app
on your AppleWatch.Tap Passcode, then tap Change Passcode and follow the onscreen prompts.
You can also open the AppleWatch app on your iPhone, tap My Watch, tap Passcode, then tap Change Passcode and follow the onscreen prompts.
Tip: To use a passcode longer than four digits, open the Settings app 
on your AppleWatch, tap Passcode, then turn off Simple Passcode.
Turn off the passcode
Open the Settings app
on your AppleWatch.Tap Passcode, then tap Turn Passcode Off.
You can also open the AppleWatch app on your iPhone, tap My Watch, tap Passcode, then tap Turn Passcode Off.
Note: If you disable your passcode, some features won’t be available. For example, you can’t use Apple Pay or unlock your Mac with your AppleWatch.
If you can’t use a simple passcode or turn off your passcode
The Simple Passcode and Turn Passcode Off buttons may be unavailable if your synced iPhone is being managed by an organization, such as a company or school. Check with your organization’s administration.
Lock automatically
By default, your AppleWatch locks automatically when you’re not wearing it. To change the wrist detection setting, do the following.
Open the Settings app
on your AppleWatch.Tap Passcode, then turn Wrist Detection on or off.
Turning off wrist detection affects these AppleWatch features:
When you use ApplePay on your AppleWatch, you’ll be prompted to enter your passcode when you double-click the side button to authorize the payment.
Some Activity measurements are unavailable.
Heart rate tracking and notifications are turned off.
AppleWatch will no longer automatically lock and unlock.
AppleWatch wonʼt automatically make an emergency call even after it has detected a hard impact fall.
Lock manually
Note: To manually lock your AppleWatch, you must turn off wrist detection. (Open the Settings app on your AppleWatch, tap Passcode, then turn off Wrist Detection.)
Press the side button to open Control Center.
Tap
.
.You must enter your passcode the next time you try to use your AppleWatch.
If you forget your passcode
If you forget your passcode, you must erase your AppleWatch. You can do so in these ways:
Unpair your AppleWatch from your iPhone to erase your watch settings and passcode, then pair again.
Reset your AppleWatch and pair it again with your iPhone.
For more information, see If you forget your AppleWatch passcode.
Erase AppleWatch after 10 unlock attempts
To protect your information if your watch is lost or stolen, you can set AppleWatch to erase its data after 10 consecutive attempts to unlock it using the wrong passcode.
Open the Settings app
on your AppleWatch.Tap Passcode, then turn on Erase Data.
If you have a Mac running macOS10.12 or later, you can unlock your computer with your Apple Watch.
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