Embodiments of the present invention provide an access method, including: sending, to an access point, a first frame that carries uplink transmission requirement information; and if a second frame that carries information about an uplink transmission resource is received from the access point within agreed time period, sending uplink multi-user transmission data to the access point, where the uplink multi-user transmission data is transmitted on the uplink transmission resource; or if the second frame is not received within an agreed time period, accessing, by a station, a channel in a contention access manner that is based on carrier sense CSMA/CA. According to the method provided in the embodiments of the present invention, a channel access manner can be managed, a congestion degree of a system can be decreased, and channel utilization can be increased.