A WLAN link adaptation method and a network device are provided, and can provide accurate link adaptation for each user in an OFDMA communications system. Embodiments of the present application include: obtaining, by a first network device, a target channel information measurement result, where the target channel information measurement result is a measurement result obtained by measuring channel information over target bandwidth; and determining, by the first network device, a modulation and coding scheme MCS of a link according to the target channel information measurement result.