how to pair apple watch to mac?

Hi

Apple Watch cannot be paired to a MacBook Pro. It can only be paired and used with an iPhone 5 or newer model of iPhone, running the latest version of iOS:

Set up your Apple Watch - Apple Support

If you are instead referring to setting up the Auto Unlock feature and if your MacBook Pro meets the system requirements for using the feature (a mid-2013 or newer Mac running macOS Sierra), then follow the instructions here:

• Automatically unlock your Mac with your Apple Watch - Apple Support
• Continuity system requirements

Enable Apple Watch to unlock Mac After that, make sure the Allow your Apple Watch to unlock your Mac box is checked. A Turning On message will then appear, and might ask you to enter your password.

Here you go: Automatically unlock your Mac with your Apple Watch - Apple Support