This application provides a channel sounding method and apparatus. The method includes: A first communication device sends a first frame to a second communication device, where the first frame is used to indicate the second communication device to perform channel sounding on a part of antennas of the first communication device. The first communication device sends a second frame to the second communication device, where the second frame is used by the second communication device to perform channel sounding on the part of antennas. The first communication device receives a third frame from the second communication device, where the third frame is used to indicate a result of performing channel sounding on the part of antennas.