This application provides a method for transmitting a paging message, a terminal device, and a network device. The method includes: determining, by a terminal device, a target paging resource, where the target paging resource includes at least one of the following types of information: position information of a target paging occasion, position information of a target paging frame, and position information of a target monitoring window; and receiving, by the terminal device, a target paging message on the target paging resource, where the target paging message is a paging message sent by a network device to the terminal device. The terminal device and the network device can be used in a communications system applying a beamforming technology, so that the terminal device can receive a paging message sent by the network device to the terminal device.