Embodiments of this disclosure provide a data transmission method, a terminal device, and a network device. The method includes: receiving, by a terminal device, indication information sent by a network device, where the indication information is used to indicate a first time domain resource used by the terminal device to send first uplink transmission; and sending, by the terminal device, the first uplink transmission to the network device on the first time domain resource, and sending second uplink transmission to the network device on a second time domain resource, where the second time domain resource is a time domain resource determined by the terminal device based on the first time domain resource, and the first time domain resource and the second time domain resource are consecutive or inconsecutive in time.