A carrier selection method and a communications device includes obtaining channel busy ratios (CBR) of a plurality of candidate carriers. The method also includes performing filtering processing on the CBRs of the plurality of candidate carriers to obtain CBRs of the plurality of candidate carriers after filtering. The method also includes selecting a carrier from the plurality of candidate carriers according to the CBRs of the plurality of candidate carriers that are obtained after filtering. Therefore, filtering processing is performed on a measurement result of the CBRs of the plurality of candidate carriers, and the carrier is selected from the plurality of candidate carriers according to the CBRs of the plurality of candidate carriers that are obtained after filtering processing, thereby reducing carrier switching frequency and ensuring system stability while the carrier is selected.