This application provides a data transmission method and apparatus. The method includes: A first access point detects a channel. If the first access point detects an idle first channel, the first access point sends a first trigger frame to at least one second access point, where the first trigger frame is used to trigger the at least one second access point to send data on the first channel after a first preset time period elapses. In this way, an existing CSMA channel detection mechanism may be compatible with the method, and a conflict caused by contention of a plurality of APs for a channel at the same time can be avoided, which helps improve network transmission efficiency, and helps improve transmission performance.