A data transmission method for an access point, wherein a transceiver of the access point comprises m transmit paths and n receive paths, the method is applied to a wireless local area network, WLAN, and the method comprises: sending (610; 710), by the access point, downlink data to at least one first station on a first channel, by using at least one of the m transmit paths within a first time; receiving (620; 720), by the access point, uplink data sent by at least one second station on a second channel, by using at least one of the n receive paths within the first time; wherein, a start time point and an end time point at which the access point sends the downlink data are respectively the same as those at which the access point receives the uplink data; performing (730; 740), by the access point, uplink or downlink transmission on the first channel within a preset time; and performing (730; 740), by the access point, uplink or downlink transmission on the second channel within the preset time, wherein the preset time is a time other than the first time, and when the access point performs uplink transmission on the first channel within the preset time, the access point performs downlink transmission on the second channel within the preset time, or when the access point performs downlink transmission on the first channel within the preset time, the access point performs uplink transmission on the second channel within the preset time; characterized in that the preset time comprises a second time, the second time is a time before a start time point of the first time, and the performing, by the access point, uplink or downlink transmission on the first channel within a preset time comprises: performing, by the access point, clear channel assessment,CCA, by using a first receive path within the second time and determining that the first channel is idle; and the performing, by the access point, uplink or downlink transmission on the second channel within the preset time comprises: performing, by the access point, clear channel assessment, CCA, by using a second receive path within the second time and determining that the second channel is idle, wherein the first receive path is at least one of any n-1 receive paths of the n receive paths, and the second receive path is at least one of the n receive paths except the first receive path. sending (610; 710), by the access point, downlink data to at least one first station on a first channel, by using at least one of the m transmit paths within a first time; receiving (620; 720), by the access point, uplink data sent by at least one second station on a second channel, by using at least one of the n receive paths within the first time; wherein, a start time point and an end time point at which the access point sends the downlink data are respectively the same as those at which the access point receives the uplink data; performing (730; 740), by the access point, uplink or downlink transmission on the first channel within a preset time; and performing (730; 740), by the access point, uplink or downlink transmission on the second channel within the preset time, wherein the preset time is a time other than the first time, and when the access point performs uplink transmission on the first channel within the preset time, the access point performs downlink transmission on the second channel within the preset time, or when the access point performs downlink transmission on the first channel within the preset time, the access point performs uplink transmission on the second channel within the preset time; characterized in that the preset time comprises a second time, the second time is a time before a start time point of the first time, and the performing, by the access point, uplink or downlink transmission on the first channel within a preset time comprises: performing, by the access point, clear channel assessment,CCA, by using a first receive path within the second time and determining that the first channel is idle; and the performing, by the access point, uplink or downlink transmission on the second channel within the preset time comprises: performing, by the access point, clear channel assessment, CCA, by using a second receive path within the second time and determining that the second channel is idle, wherein the first receive path is at least one of any n-1 receive paths of the n receive paths, and the second receive path is at least one of the n receive paths except the first receive path. performing, by the access point, clear channel assessment,CCA, by using a first receive path within the second time and determining that the first channel is idle; and the performing, by the access point, uplink or downlink transmission on the second channel within the preset time comprises: performing, by the access point, clear channel assessment, CCA, by using a second receive path within the second time and determining that the second channel is idle, wherein the first receive path is at least one of any n-1 receive paths of the n receive paths, and the second receive path is at least one of the n receive paths except the first receive path. performing, by the access point, clear channel assessment, CCA, by using a second receive path within the second time and determining that the second channel is idle, wherein the first receive path is at least one of any n-1 receive paths of the n receive paths, and the second receive path is at least one of the n receive paths except the first receive path.