In one embodiment, a method includes: sending, by a first communications device, B synchronization signal blocks to a second communications device by using A transmit beams, where each of the B synchronization signal blocks includes an identifier of the first communications device and receive beam time sequence information of the first communications device, and wherein the receive beam time sequence information indicates a time sequence location at which the first communications device receives feedback information; receiving first feedback information from the second communications device based on the time sequence location by using C receive beams; determining a first receive beam based on a receive beam that is in the C receive beams and on which the first feedback information is received; and determining a first transmit beam based on the first receive beam or the first feedback information, where the first transmit beam belongs to the A transmit beams.