Disclosed are a channel state information reporting method and device, relating to the field of wireless communications and used for solving the problem of no corresponding CSI reporting method being provided at present regarding a Rel-16 codebook structure. The method of the present application includes a terminal determining, according to codebook parameter information, codebook indication information corresponding to a data transmission layer; and the terminal sending channel state information (CSI) including the codebook indication information to a network side device, and the codebook indication information includes a part or all of the following: beam information for determining a precoding matrix orthogonal combination beam, base vector information for determining a precoding matrix compression base vector, and nonzero coefficient indication information for determining a precoding matrix compression coefficient.