On the source Mac, save the login.keychain-db file located in ~/Library/Keychains on an external drive or in the cloud. On the destination Mac, open Keychain Access. From the File menu, choose Add Keychain. Browse to the folder where you saved the keychain file from the other Mac. Click Add.
1) On the source Mac, open Finder.
2) In your Mac's menu bar, click Go and choose Go to Folder.
3) Type the following path and click Go:
4) Copy the login.keychain-db file to a new Mac. You can do this using an external drive or iCloud.
NOTE: In this example, we are using an external flash drive. Just click, hold, and drag to the desired location.
5) On the destination Mac, open the Keychain Access app. One way to do this is by going to Launchpad, going to the Other folder, and clicking Keychain Access.
6) From the File menu, choose Add Keychain.
7) Browse to the keychain file that you copied and choose Add to import the stored keychain data to your destination Mac.
All of the stored passwords and sign-in information from the original Mac should be imported to the destination Mac and ready to use.