A data transmission method, including: receiving, by a terminal device on a first time domain resource, at least one piece of downlink data sent by a network device; and sending receiving status information to the network device on a second time domain resource. A transmission time interval of any piece of downlink data is less than a transmission time interval of the receiving status information, and the transmission time interval of the any piece of downlink data is less than 1 ms. According to the data transmission method, a transmission time interval of downlink data and a time interval between a sending time of the receiving status information and a receiving time of the at least one piece of downlink data are shortened, thereby reducing a latency.