A transmission method and a communications device, and the method includes sending a first data frame to a second communications device using an unlicensed carrier, and sending M second data frames to the second communications device using a licensed carrier, where at least one data frame in the M second data frames carries first information, the first information includes information required for detecting the first data frame by the second communications device, and M is an integer not less than 1. According to the transmission method and the communications device, the energy consumption of the communications device can be reduced.