A method for trusted network access control based upon tri-element peer authentication, comprising: initializing Trustworthiness Measurement Collectors, TMCs, at a trustworthiness measurement layer; executing a tri-element peer authentication protocol based on a policy manager acting as a third party by an access requester, an access controller and the policy manager at a network access control layer to perform bidirectional user authentication between the access requester and the access controller; when results of the user authentication indicate successful authentication, executing the tri-element peer authentication protocol based on the policy manager acting as a third party by the access requester, the access controller and the policy manager at a trusted platform evaluation layer to perform bidirectional platform trustworthiness evaluation between the access requester and the access controller; generating by a TNAC client of the access requester and a TNAC server of the access controller according to results of platform trustworthiness evaluation in the platform trustworthiness evaluation process and transmitting corresponding recommendations respectively to the access requester and the access controller so that the network access requester and the network access controller control mutual access ports respectively according to the recommendations; wherein port control is performed as follows: an uncontrolled port of the access requester controls transport of user authentication and session key negotiation protocols data, a platform trustworthiness evaluation protocol data and platform remediation server data, and a controlled port of the access requestor controls transport of application service data; and an uncontrolled port of the access controller controls transport of the user authentication and session key negotiation protocols data, and a controlled port of the access controller controls transport of the platform trustworthiness evaluation protocol data, platform remediation service data and application service data. initializing Trustworthiness Measurement Collectors, TMCs, at a trustworthiness measurement layer; executing a tri-element peer authentication protocol based on a policy manager acting as a third party by an access requester, an access controller and the policy manager at a network access control layer to perform bidirectional user authentication between the access requester and the access controller; when results of the user authentication indicate successful authentication, executing the tri-element peer authentication protocol based on the policy manager acting as a third party by the access requester, the access controller and the policy manager at a trusted platform evaluation layer to perform bidirectional platform trustworthiness evaluation between the access requester and the access controller; generating by a TNAC client of the access requester and a TNAC server of the access controller according to results of platform trustworthiness evaluation in the platform trustworthiness evaluation process and transmitting corresponding recommendations respectively to the access requester and the access controller so that the network access requester and the network access controller control mutual access ports respectively according to the recommendations; an uncontrolled port of the access requester controls transport of user authentication and session key negotiation protocols data, a platform trustworthiness evaluation protocol data and platform remediation server data, and a controlled port of the access requestor controls transport of application service data; and an uncontrolled port of the access controller controls transport of the user authentication and session key negotiation protocols data, and a controlled port of the access controller controls transport of the platform trustworthiness evaluation protocol data, platform remediation service data and application service data.