A channel measurement method includes a network device obtains first information and obtains third downlink channel information based on the first information. The first information is obtained based on second information and third information, the second information is obtained based on first downlink channel information obtained by a terminal device through measurement, and the third information is obtained based on uplink channel information and/or second downlink channel information obtained by the terminal device through measurement. The network device considers auxiliary information in a process of reconstructing downlink channel information, so that precision of the reconstructed channel information is improved.