A method for feeding back information about a channel between antenna arrays is provided, which includes: receiving, by a first network device, sub-channel channel information of N×M sub-channels that is sent by a second network device, where an antenna array of the first network device includes M panels, an antenna array of the second network device includes N panels, the channel between the first network device and the second network device includes the N×M sub-channels, M is a positive integer that is greater than or equal to 2, N is and N is a positive integer, M and N are not to be 1 at the same time, and the M panels and the N panels each includes at least two antennas; generating channel information of the channel between the first network device and the second network device according to the sub-channel channel information of the N×M sub-channels.