This application provides a resource indication method, a terminal device, and a network device. The method includes: determining, by a network device, first indication information, and sending the first indication information to a terminal device, where the first indication information is used to indicate a time domain location occupied in a resource unit by a component pattern of a reference signal; and receiving, by the terminal device, the first indication information, and determining, based on the first indication information, the time domain location occupied in the resource unit by the reference signal. The resource indication method, the terminal device, and the network device in the embodiments of this application help implement a plurality of different mapping modes of a reference signal.