A channel state information feedback method includes: generating, by a transmit-end device, codebook indication information of K transport layers, where K is an integer greater than or equal to 1; and for each of at least one of the K transport layers, the codebook indication information includes narrowband superposition coefficients of N sub-bands of the layer, where a quantity of the narrowband superposition coefficients of the N sub-bands is less than R(L−1)*N, N is an integer greater than or equal to 2, R is a quantity of polarization directions and R is an integer greater than or equal to 1, and L is a quantity of pieces of beam information used by the K transport layers and L is an integer greater than or equal to 2; and sending, by the transmit-end device, the codebook indication information.