Embodiments of this application provide a retransmission method and a device. After receiving feedback information transmitted by a receiving device based on first information indicated by a retransmission mode, a transmitting device uses second information indicated by the retransmission mode to generate data, and transmits the data to the receiving device based on third information indicated by the retransmission mode. In this process, a plurality of retransmission modes are set, so that when different retransmission modes are used, the first information used for transmitting the feedback information, the second information used for generating the retransmitted data, or the third information used for transmitting the retransmitted data is different. Therefore, objectives of reducing HARQ overheads and ensuring transmission efficiency, reliability, and latency performance of a wireless communications system are achieved.