A channel state information feedback method, comprising: - receiving, by user equipment, UE, N first reference signal resources configured by a base station, wherein each of the N first reference signal resources comprises at least one port, and N is an integer greater than or equal to 2, and wherein the N first reference signal resources correspond to beams in different directions; - determining, by the UE, a channel state indication, CSI, and M pieces of first reference signal resource indication information based on a feedback mode, wherein M is an integer less than or equal to N, and the CSI comprises at least one of the following elements: a rank indicator, RI, a precoding matrix indicator, PMI, a channel quality indicator, CQI, a channel covariance matrix, or a channel eigenvector, wherein the feedback mode comprises one of a first feedback mode and a second feedback mode; wherein, according to the first feedback mode, the UE determines at least one element in the CSI based on the N first reference signal resources, and the M pieces of first reference signal resource indication information based on the at least one element in the CSI; wherein, according to the second feedback mode, the UE determines the M pieces of first reference signal resource indication information based on the N first reference signal resources, and the CSI based on the M first reference signal resources indicated by the M pieces of first reference signal resource indication information; and wherein the M pieces of first reference signal resource indication information are M beam identifiers; and - reporting, by the UE, the CSI of the M first reference signal resources in a horizontal dimension and the M pieces of first reference signal resource indication information to the base station, so that the base station determines channel state information in a vertical dimension based on the first reference signal resource indication information. - receiving, by user equipment, UE, N first reference signal resources configured by a base station, wherein each of the N first reference signal resources comprises at least one port, and N is an integer greater than or equal to 2, and wherein the N first reference signal resources correspond to beams in different directions; - determining, by the UE, a channel state indication, CSI, and M pieces of first reference signal resource indication information based on a feedback mode, wherein M is an integer less than or equal to N, and the CSI comprises at least one of the following elements: a rank indicator, RI, a precoding matrix indicator, PMI, a channel quality indicator, CQI, a channel covariance matrix, or a channel eigenvector, wherein the feedback mode comprises one of a first feedback mode and a second feedback mode; wherein, according to the first feedback mode, the UE determines at least one element in the CSI based on the N first reference signal resources, and the M pieces of first reference signal resource indication information based on the at least one element in the CSI; wherein, according to the second feedback mode, the UE determines the M pieces of first reference signal resource indication information based on the N first reference signal resources, and the CSI based on the M first reference signal resources indicated by the M pieces of first reference signal resource indication information; and wherein the M pieces of first reference signal resource indication information are M beam identifiers; and wherein the feedback mode comprises one of a first feedback mode and a second feedback mode; wherein, according to the first feedback mode, the UE determines at least one element in the CSI based on the N first reference signal resources, and the M pieces of first reference signal resource indication information based on the at least one element in the CSI; wherein, according to the second feedback mode, the UE determines the M pieces of first reference signal resource indication information based on the N first reference signal resources, and the CSI based on the M first reference signal resources indicated by the M pieces of first reference signal resource indication information; and wherein the M pieces of first reference signal resource indication information are M beam identifiers; and - reporting, by the UE, the CSI of the M first reference signal resources in a horizontal dimension and the M pieces of first reference signal resource indication information to the base station, so that the base station determines channel state information in a vertical dimension based on the first reference signal resource indication information.