This application provides a data transmission method and a communications apparatus. The method includes: generating, by an access point, a physical protocol data unit PPDU, where a data part of the PPDU is carried on at least one resource unit RU; sending, by the access point, the PPDU to at least one station by using a channel bandwidth, where the channel bandwidth includes M basic bandwidths, the basic bandwidth is 2.16 GHz, M is an integer greater than or equal to 1, and the M basic bandwidths are divided into the at least one RU; and parsing, by the station, the data part that is of the PPDU and that is carried on the at least one RU. In embodiments of this application, it can implement an OFDMA technology in a high-frequency scenario, and improve channel utilization and transmission efficiency.