The present invention discloses a method, a network device, and a user equipment for controlling access to a core network. The method includes: determining that a change occurs in access control information for controlling a user equipment to access a core network; and sending radio resource control signaling to the user equipment through a dedicated control channel, where the radio resource control signaling is used to notify the user equipment that a change occurs in the access control information, so that the user equipment updates the access control information. Therefore, a load of a core network node can be effectively controlled, and system performance is improved.