A communication method, implemented by a terminal device, comprising: determining a target precoding matrix in a pre-generated codebook and a precoding matrix indicator information, wherein the precoding matrix indicator information is used to indicate the target precoding matrix and a parameter value that corresponds to a block codebook difference parameter, said block codebook difference parameter providing information about a phase difference between different corresponding antenna panels, wherein the target precoding matrix in the codebook satisfies: W l, m, n, θ 1, ⋯, θ N − 1 1 = 1 2 NK 1 K 2 ν l ⊗ u m φ n ν l ⊗ u m e jθ 1 ν l ⊗ u m φ n ν l ⊗ u m ⋮ ⋮ e jθ N − 1 ν l ⊗ u m φ n ν l ⊗ u m. wherein a superscript of W represents a rank number; φ n = e jπn / 2 represents a phase difference or a phase factor between two polarization directions of an antenna, wherein a value range of n satisfies {0, 1, 2, 3}; 1 and m each represent a function of a first PMI; e represents a natural constant; j represents a unit imaginary number; π represents the circular ratio; ν l = 1 e j 2 πl O 1 K 1 ⋯ e j 2 πl K 1 − 1 O 1 ⋅ K 1 T, wherein ν l represents a DFT vector whose length is K 1, a k 1 th element of v1 is e j 2 πlk 1 O 1 K 1, a value of ki is {1, 2,..., K 1 - 1}, and K 1 is a quantity of CSI-RS ports in a horizontal dimension in each antenna port group; u m = 1 e j 2 πm O 2 K 2 ⋯ e j 2 πm K 2 − 1 O 2 ⋅ K 2 T, wherein u m represents a DFT vector whose length is K 2, a k2 th element of u m is e j 2 πlk 2 O 1 K 1, a value of k 2 is { 1, 2,..., K 2 - 1}, and K 2 is a quantity of CSI-RS ports in a vertical dimension in each group; ( θ 1... θ N- 1) represent phase differences or phase factors between different antenna port groups, or represent phase differences between block codebooks, or represent phase differences or phase factors between antenna panels; θ r =2 πi 1, r +2 / X, wherein r = 1,···, N -1, and X is a value in a set {2, 4, 8,...}; O 1 and O 2 represent over-sampling factors; X represents a Kronecker product; and N represents the quantity of antenna port groups, or represents a quantity of antenna panels, or N is 2 or 4; and, sending the precoding matrix indicator information to a radio access network device. determining a target precoding matrix in a pre-generated codebook and a precoding matrix indicator information, wherein the precoding matrix indicator information is used to indicate the target precoding matrix and a parameter value that corresponds to a block codebook difference parameter, said block codebook difference parameter providing information about a phase difference between different corresponding antenna panels, wherein the target precoding matrix in the codebook satisfies: W l, m, n, θ 1, ⋯, θ N − 1 1 = 1 2 NK 1 K 2 ν l ⊗ u m φ n ν l ⊗ u m e jθ 1 ν l ⊗ u m φ n ν l ⊗ u m ⋮ ⋮ e jθ N − 1 ν l ⊗ u m φ n ν l ⊗ u m. wherein a superscript of W represents a rank number; φ n = e jπn / 2 represents a phase difference or a phase factor between two polarization directions of an antenna, wherein a value range of n satisfies {0, 1, 2, 3}; 1 and m each represent a function of a first PMI; e represents a natural constant; j represents a unit imaginary number; π represents the circular ratio; ν l = 1 e j 2 πl O 1 K 1 ⋯ e j 2 πl K 1 − 1 O 1 ⋅ K 1 T, wherein ν l represents a DFT vector whose length is K 1, a k 1 th element of v1 is e j 2 πlk 1 O 1 K 1, a value of ki is {1, 2,..., K 1 - 1}, and K 1 is a quantity of CSI-RS ports in a horizontal dimension in each antenna port group; u m = 1 e j 2 πm O 2 K 2 ⋯ e j 2 πm K 2 − 1 O 2 ⋅ K 2 T, wherein u m represents a DFT vector whose length is K 2, a k2 th element of u m is e j 2 πlk 2 O 1 K 1, a value of k 2 is { 1, 2,..., K 2 - 1}, and K 2 is a quantity of CSI-RS ports in a vertical dimension in each group; ( θ 1... θ N- 1) represent phase differences or phase factors between different antenna port groups, or represent phase differences between block codebooks, or represent phase differences or phase factors between antenna panels; θ r =2 πi 1, r +2 / X, wherein r = 1,···, N -1, and X is a value in a set {2, 4, 8,...}; O 1 and O 2 represent over-sampling factors; X represents a Kronecker product; and N represents the quantity of antenna port groups, or represents a quantity of antenna panels, or N is 2 or 4; and, sending the precoding matrix indicator information to a radio access network device.