This application provides a method for restricting access of a terminal device, and an apparatus. The method includes: receiving, by an access network device, a first identifier that is from a terminal device, where the first identifier is used to identify the terminal device; and if the first identifier matches a second identifier, restricting, by the access network device, access of the terminal device, where the second identifier is used to identify a terminal device having abnormal behavior. Based on the solution, the access network device pre-records the second identifier of the terminal device having the abnormal behavior.