This invention relates to a peer-to-peer access control method of a triple-unit structure for safely implementing bidirectional authentication between the terminal and the network. According to the method, on the basis of the access control method of the existing double-unit triple-entity structure, the authenticator function is implemented in the access controller, and the authentication protocol function is implemented in the terminal and the access controller, so that the terminal, the access controller and the server all participate in the authentication, and the trust relationship is established between the terminal and the access controller directly, which renders security very reliable. The invention not only solves the technical problems of the access control method of the existing double-unit double-entity structure that the access flexibility is limited and the extension of the number of the access controllers is inconvenient, but also solves the technical problems of the existing access control method of the double-unit triple-entity structure that the process for establishing the trust relationship is complicated and the security of the network may be influenced, thus achieving advantages of high security performance, no requirement of changing existing network structures and relative independency of the authentication protocol.