This application provides a resource mapping method, a network device, and a terminal device. The method includes: generating, by a network device, control information, where the control information is used to indicate at least one type of the following information: at least one bandwidth region in which at least one frequency domain resource unit is located, a granularity of the frequency domain resource unit, and a location of the frequency domain resource unit in the bandwidth region; and sending, by the network device, the control information to a terminal device. The frequency domain resource unit is a scheduling unit of a frequency domain resource used when the network device and the terminal device transmit a data channel. The granularity of the resource unit corresponds to a granularity of a resource unit used when the network device and the terminal device transmit a control channel.