A trusted network access control system based on tri-element peer authentication system, wherein the system comprises an access requestor AR, an access controller AC and a policy manager PM, wherein the PM is adapted to verify validity of attestation identity key AIK certificates of the AR and the AC and check platform trustworthiness of the AR and the AC; the AR is connected with the AC through a protocol interface via network, the AC is connected with the PM through a protocol interface via network, and the AR is connected with the PM through the AC via network; the protocol interface connecting the AR with the AC comprises: a trusted network transport interface IF-TNT and an interface IF-TNACCS between a TNAC client and a TNAC sever; the IF-TNT is an information exchanging interface between a network access requestor NAR and a network access controller NAC on a network access control layer, and the IF-TNACCS is an information exchanging interface between the TNAC client and the TNAC server on a trusted platform evaluation layer; the protocol interface between the AC and the PM comprises: an authentication policy service interface IF-APS, an evaluation policy service interface IF-EPS and a trustworthiness measurement interface IF-TM; the IF-APS is an information exchanging interface between a network access controller NAC and an authentication policy server APS on the network control layer, and the IF-EPS is an information exchanging interface between a TNC server and an evaluation policy server EPS on the trusted platform evaluation layer; and the IF-TM is an interface between a trustworthiness measurement collector and a trustworthiness measurement verifier on the trustworthiness measurement layer; the protocol interface connecting the AR with the PM comprises a trustworthiness measurement interface IF-TM, and the IF-TM is an interface between the trustworthiness measurement collector and the trustworthiness measurement verifier on the trustworthiness measurement layer; wherein uncontrolled ports of the access requestor pass through user authentication and key negotiation protocol data, trusted platform evaluation protocol data and platform repair server data, controlled ports of the access requestor pass through application server data; uncontrolled ports of the access controller pass through the user authentication and key negotiation protocol data, and controlled ports of the access controller implement passage control of the trusted platform evaluation protocol data, platform makeup repair service data and application service data in a multi-level control manner. the PM is adapted to verify validity of attestation identity key AIK certificates of the AR and the AC and check platform trustworthiness of the AR and the AC; the AR is connected with the AC through a protocol interface via network, the AC is connected with the PM through a protocol interface via network, and the AR is connected with the PM through the AC via network; the protocol interface connecting the AR with the AC comprises: a trusted network transport interface IF-TNT and an interface IF-TNACCS between a TNAC client and a TNAC sever; the IF-TNT is an information exchanging interface between a network access requestor NAR and a network access controller NAC on a network access control layer, and the IF-TNACCS is an information exchanging interface between the TNAC client and the TNAC server on a trusted platform evaluation layer; the protocol interface between the AC and the PM comprises: an authentication policy service interface IF-APS, an evaluation policy service interface IF-EPS and a trustworthiness measurement interface IF-TM; the IF-APS is an information exchanging interface between a network access controller NAC and an authentication policy server APS on the network control layer, and the IF-EPS is an information exchanging interface between a TNC server and an evaluation policy server EPS on the trusted platform evaluation layer; and the IF-TM is an interface between a trustworthiness measurement collector and a trustworthiness measurement verifier on the trustworthiness measurement layer; the protocol interface connecting the AR with the PM comprises a trustworthiness measurement interface IF-TM, and the IF-TM is an interface between the trustworthiness measurement collector and the trustworthiness measurement verifier on the trustworthiness measurement layer; wherein uncontrolled ports of the access requestor pass through user authentication and key negotiation protocol data, trusted platform evaluation protocol data and platform repair server data, controlled ports of the access requestor pass through application server data; uncontrolled ports of the access controller pass through the user authentication and key negotiation protocol data, and controlled ports of the access controller implement passage control of the trusted platform evaluation protocol data, platform makeup repair service data and application service data in a multi-level control manner.