The invention provides a method and system for controlling the user network access authority, including the presetting phase: the corresponding relationship between the network equipment configuration address portion and the network access authority; the corresponding relationship between the combination configured unique user equipment identifier for RADIUS server and DHCP server and address pool information. After the user authentication, IP address allocation phase for dynamic address request and network access authority selection, controlling of user network access authority: the DHCP server and RADIUS server may get the address pool information according to the unique identifier of user equipment and return to the user equipment, the user equipment may get the network access authority for corresponding network equipment configuration according to this address pool information. With the invention, directly control during the authentication, and dynamic address acquisition, simply and effectively realize the network access authority control for different user authenticated, simplify the dependency for network equipment.