Embodiments of the present invention relates to the field of communications. Provided are a data transmission method and apparatus. The method comprises the following steps: a first station receives multi-user request to send (MU-RTS) frames sent by an access point, the MU-RTS frames comprising identifiers of multiple stations and scheduled transmission channels of each station; the first station determines scheduled stations of the first station according to the identifiers of the multiple stations; when it is determined that the scheduled transmission channels of the first station comprise main channels, the first station sends clear to send (CTS) frames to the access point on the scheduled transmission channels of the first station; and when it is determined that the scheduled transmission channels of the first station do not comprise the main channels, the first station sends CTS frames to the access point on the main channels and the scheduled transmission channels of the first station or sends CTS frames on minimum continuous channels comprising the main channels and the scheduled transmission channels, so as to acquire path information of service packets. By using the present invention, main channels can be effectively protected, and excessive protection on transmission channels can be avoided, thereby improving the resource utilization rate of a system.