A channel state information reporting method, comprising: determining, by a terminal, R first precoding matrix indicators PMIs based on M first reference signal resources, and determining at least one channel quality indicator CQI based on the R first PMIs, wherein M and R are integers greater than 1; and reporting, by the terminal, channel state information, wherein the channel state information comprises the R first PMIs and N CQIs, the R first PMIs are used by a base station to determine P second PMIs, a dimension of each of the P second PMIs is greater than a dimension of each of the R first PMIs, which indicates that a quantity of rows of a precoding matrix of each of the P second PMIs is greater than a quantity of rows of a precoding matrix of each of the R first PMIs; and P and N are integers greater than or equal to 1, wherein if the channel state information comprises the R first PMIs and a plurality of CQIs, the determining the at least one channel quality indicator CQI based on the R first PMIs comprises: determining, by the terminal, the P second PMIs and the plurality of CQIs based on the R first PMIs and a first operational criterion; and if the channel state information comprises the R first PMIs and one CQI, the determining the at least one channel quality indicator CQI based on the R first PMIs comprises: determining, by the terminal, one second PMI and the CQI based on the R first PMIs and a second operational criterion; wherein the first operational criterion and the second operational criterion comprise at least one of a direct product, a direct sum, and an interpolation, and wherein the first operational criterion and the second operational criterion are configured by the base station for the terminal, or the first operational criterion and the second operational criterion are predefined by the base station and the terminal. determining, by a terminal, R first precoding matrix indicators PMIs based on M first reference signal resources, and determining at least one channel quality indicator CQI based on the R first PMIs, wherein M and R are integers greater than 1; and reporting, by the terminal, channel state information, wherein the channel state information comprises the R first PMIs and N CQIs, the R first PMIs are used by a base station to determine P second PMIs, a dimension of each of the P second PMIs is greater than a dimension of each of the R first PMIs, which indicates that a quantity of rows of a precoding matrix of each of the P second PMIs is greater than a quantity of rows of a precoding matrix of each of the R first PMIs; and P and N are integers greater than or equal to 1, wherein if the channel state information comprises the R first PMIs and a plurality of CQIs, the determining the at least one channel quality indicator CQI based on the R first PMIs comprises: determining, by the terminal, the P second PMIs and the plurality of CQIs based on the R first PMIs and a first operational criterion; and if the channel state information comprises the R first PMIs and one CQI, the determining the at least one channel quality indicator CQI based on the R first PMIs comprises: determining, by the terminal, one second PMI and the CQI based on the R first PMIs and a second operational criterion; wherein the first operational criterion and the second operational criterion comprise at least one of a direct product, a direct sum, and an interpolation, and wherein the first operational criterion and the second operational criterion are configured by the base station for the terminal, or the first operational criterion and the second operational criterion are predefined by the base station and the terminal. determining, by the terminal, the P second PMIs and the plurality of CQIs based on the R first PMIs and a first operational criterion; and if the channel state information comprises the R first PMIs and one CQI, the determining the at least one channel quality indicator CQI based on the R first PMIs comprises: determining, by the terminal, one second PMI and the CQI based on the R first PMIs and a second operational criterion; wherein the first operational criterion and the second operational criterion comprise at least one of a direct product, a direct sum, and an interpolation, and wherein the first operational criterion and the second operational criterion are configured by the base station for the terminal, or the first operational criterion and the second operational criterion are predefined by the base station and the terminal. determining, by the terminal, one second PMI and the CQI based on the R first PMIs and a second operational criterion; wherein the first operational criterion and the second operational criterion comprise at least one of a direct product, a direct sum, and an interpolation, and wherein the first operational criterion and the second operational criterion are configured by the base station for the terminal, or the first operational criterion and the second operational criterion are predefined by the base station and the terminal.