A channel measurement method, wherein a wireless communications system comprises a channel measurement apparatus and at least two user equipments, the method comprising: sending, by the channel measurement apparatus, an antenna domain training sequence to the at least two user equipments, wherein the antenna domain training sequence is a time domain sequence for measuring a channel; receiving, by the channel measurement apparatus, channel response measurement sequences sent by the at least two user equipments, wherein the channel response measurement sequences are sequences that are obtained after the antenna domain training sequence passes through channels and that are received by the at least two user equipments; and transforming, by the channel measurement apparatus, the antenna domain training sequence to obtain an angular domain training sequence; performing, by the channel measurement apparatus, processing on a channel response measurement sequence of each user equipment according to a sparsity set and the angular domain training sequence, to obtain a shared channel support set and a first residue of each user equipment, wherein the first residue is a residue obtained after a measurement value component generated for a channel response in the shared channel support set is subtracted, wherein the sparsity set is a preset set of quantities of non-zero columns in angular domain channel state matrices of the user equipments; obtaining, by the channel measurement apparatus, a channel support set of each user equipment according to the angular domain training sequence, the shared channel support set, the first residue of each user equipment, and the sparsity set; and obtaining, by the channel measurement apparatus, an angular domain channel state matrix of each user equipment according to the channel support set of each user equipment, the angular domain training sequence, and the received channel response measurement sequence of each user equipment; and transforming, by the channel measurement apparatus, the angular domain channel state matrix of each user equipment to obtain downlink channel state information, CSI (S 102). sending, by the channel measurement apparatus, an antenna domain training sequence to the at least two user equipments, wherein the antenna domain training sequence is a time domain sequence for measuring a channel; receiving, by the channel measurement apparatus, channel response measurement sequences sent by the at least two user equipments, wherein the channel response measurement sequences are sequences that are obtained after the antenna domain training sequence passes through channels and that are received by the at least two user equipments; and transforming, by the channel measurement apparatus, the antenna domain training sequence to obtain an angular domain training sequence; performing, by the channel measurement apparatus, processing on a channel response measurement sequence of each user equipment according to a sparsity set and the angular domain training sequence, to obtain a shared channel support set and a first residue of each user equipment, wherein the first residue is a residue obtained after a measurement value component generated for a channel response in the shared channel support set is subtracted, wherein the sparsity set is a preset set of quantities of non-zero columns in angular domain channel state matrices of the user equipments; obtaining, by the channel measurement apparatus, a channel support set of each user equipment according to the angular domain training sequence, the shared channel support set, the first residue of each user equipment, and the sparsity set; and obtaining, by the channel measurement apparatus, an angular domain channel state matrix of each user equipment according to the channel support set of each user equipment, the angular domain training sequence, and the received channel response measurement sequence of each user equipment; and transforming, by the channel measurement apparatus, the angular domain channel state matrix of each user equipment to obtain downlink channel state information, CSI (S 102).