A paging method, a paging device, and system are described. A mobility management network element (MME) obtains location information of user equipment (UE) in a non-3rd Generation Partnership Project (3GPP) network, where the UE already accesses the non-3GPP network. The MME receives a downlink data notification message, where the downlink data notification message carries an identifier of the UE. The MME pages the UE according to the location information of the UE in the non-3GPP network. In some implementations, a paging range may be determined according to the location information of the UE in the non-3GPP network, and a paging message does not need to be sent to all base stations in a registration area of the UE.