Method and system for registration or login via third-party website

The invention discloses a method and a system for registration or login via a third-party website, and belongs to the field of the internet. The method includes that a verification link for using the third-party website for verifying account numbers is set on a registration webpage of a source website, a user jumps to the third-party website after triggering the verification link, and logins the third-party website by using a third-party account number, the account number is verified, and authority for reading personal information is granted to the user; the source website acquires the authorized personal information of the user from the third-party website via a port provided by the third-party website; then the source website fills the personal information in corresponding registration information of the registration webpage and stores the personal information, and registration is completed; or the source website judges whether the user is a registered user of the source website or not according to the personal information, a session key is generated if the user is the registered user, a login status is displayed, and login is completed. The method and the system have the advantages that when the user is registered via the third-party website, the amount of information required to be inputted by the user in a website registration process is reduced, and the registration efficiency is improved.