An access control method for a TePA-based TNC architecture is provided, including: 1) performing encapsulation of user authentication protocol data and platform authentication protocol data in the TePA-based TNC architecture: 1.1) encapsulating the user authentication protocol data in a Data field of TAEP packets, and interacting with the TAEP packets between an access requestor and an access controller, and between the access controller and a policy manager, to perform mutual user authentication between the access requestor and the access controller, and establish a secure channel between the access requestor and the access controller; and 1.2) encapsulating the platform authentication protocol data in a Data field of TAEP packets, and, for platform authentication protocol data between the access requestor and the access controller, encapsulating a TAEP packet of the platform authentication protocol data in a Data field of another TAEP packet to form a nested encapsulation.