A sector level sweep method and apparatus are provided. A local end generates a first sector sweep packet at the local end sector sweep stage, and the local end sends the first sector sweep packet to a peer end by using a first beam. A quantity of bytes of the first sector sweep packet is not greater than 27, the first sector sweep packet includes beam indication information of the first beam, the beam indication information includes antenna identification information of the beam, and a maximum quantity of antennas indicated by the antenna identification information is at least 8.