A method and a device for performing codebook processing on channel information are described, wherein channel information obtained by channel estimation is analysed to obtain a value space and a null space; the value space or the null space of which a dimension is small is taken as a codebook space; a codebook space vector is selected; and multidimensional codebook processing is performed separately on each codebook space vector, and information obtained by performing codebook is fed back to a base station. Thus the channel information feedback quantity and the codebook precision can be balanced flexibly without expanding codebook capacity, and the codebook precision is improved and channel information distortion is deduced under a premise that channel information data quantity is reduced.