A channel measurement method, comprising: determining, by a terminal device, L weighting coefficients, wherein the L weighting coefficients are used to determine channels of K moments based on channels of M moments, and L, M, and K are all integers greater than or equal to 1, and wherein the channels of the M moments are channels obtained through measurement, and channels of the K moments are channels obtained through the L weighting coefficients and the channels of the M moments obtained through measurement; wherein the L weighting coefficients are determined based on reference signals received N times, wherein N is an integer greater than or equal to 1 and greater than or equal to L, and determining the L weighting coefficients comprises: performing channel measurements based on a reference signal received at an nth time in N times to obtain a spatial-frequency matrix H(n), wherein n is an integer greater than or equal to 1 and less than or equal to N, and the L weighting coefficients are determined based on the spatial-frequency matrix H(n) as: H 1 ⋯ H L ⋮ ⋱ ⋮ H O ⋯ H O + L − 1 a 1 ⋮ a L = H L + 1 ⋮ H O + L wherein {a1,..., aL} are the L weighting coefficients, H to H(O+L) are all known measurement channels, and O represents a quantity of equations used to calculate the L weighting coefficients; and the method further comprises: sending, by the terminal device, information about the L weighting coefficients and the channels of the M moments. determining, by a terminal device, L weighting coefficients, wherein the L weighting coefficients are used to determine channels of K moments based on channels of M moments, and L, M, and K are all integers greater than or equal to 1, and wherein the channels of the M moments are channels obtained through measurement, and channels of the K moments are channels obtained through the L weighting coefficients and the channels of the M moments obtained through measurement; wherein the L weighting coefficients are determined based on reference signals received N times, wherein N is an integer greater than or equal to 1 and greater than or equal to L, and determining the L weighting coefficients comprises: performing channel measurements based on a reference signal received at an nth time in N times to obtain a spatial-frequency matrix H(n), wherein n is an integer greater than or equal to 1 and less than or equal to N, and the L weighting coefficients are determined based on the spatial-frequency matrix H(n) as: H 1 ⋯ H L ⋮ ⋱ ⋮ H O ⋯ H O + L − 1 a 1 ⋮ a L = H L + 1 ⋮ H O + L wherein {a1,..., aL} are the L weighting coefficients, H to H(O+L) are all known measurement channels, and O represents a quantity of equations used to calculate the L weighting coefficients; and the method further comprises: sending, by the terminal device, information about the L weighting coefficients and the channels of the M moments. performing channel measurements based on a reference signal received at an nth time in N times to obtain a spatial-frequency matrix H(n), wherein n is an integer greater than or equal to 1 and less than or equal to N, and the L weighting coefficients are determined based on the spatial-frequency matrix H(n) as: H 1 ⋯ H L ⋮ ⋱ ⋮ H O ⋯ H O + L − 1 a 1 ⋮ a L = H L + 1 ⋮ H O + L wherein {a1,..., aL} are the L weighting coefficients, H to H(O+L) are all known measurement channels, and O represents a quantity of equations used to calculate the L weighting coefficients; and the method further comprises: sending, by the terminal device, information about the L weighting coefficients and the channels of the M moments.