Embodiments of the present invention disclose a paging method, a core network device, a base station, and user equipment. The method includes: determining, by the core network device, reference frame information when the core network device determines that a synchronization occasion arrives, where the reference frame information includes a radio frame number; and sending, by the core network device, the reference frame information to a base station in a paging area, so that the base station synchronizes a radio frame in the base station according to the reference frame information. The embodiments of the present invention can reduce problems that UE cannot listen for a paging message.