Method for authenticating user identity through P2P service request

The invention relates to a method for authenticating user identity through P2P service request. The prior P2P network authentication mode has certain limitations. The method for authenticating user identity comprises steps of: user registration, namely, a user obtains a legal account number after submitting a registration request to a server, and the user can log in a P2P network to acquire services by using the account number; login authentication, namely, the user inputs a user name and a password on a host computer provided with client software to log in an authentication server and perform identity authentication, and the login authentication comprises local login and server authentication; and service request authentication, namely, the user receiving a resource service request from the P2P network queries the authentication server to authenticate the identity of the user sending the request. The method adopts dual authentication in the process of the user identity authentication, so the safety factor is higher, and the same account number can be prevented from being logged in by a plurality of users at the same time; besides, the authentication server has no need of saving the password of the user, so the account number and the password of the user cannot be given away.