This application provides an information feedback method and a related apparatus. In the method, a first apparatus sends, to a second apparatus, a first frame that carries a first field used to perform channel estimation, and the first apparatus receives a first feedback frame from the second apparatus. The first feedback frame includes channel state information CSI, the CSI is CSI from the first apparatus to the second apparatus, the CSI is obtained by the second apparatus by performing channel estimation based on the received first field and a second field, and the second field is not the first field.