A multi-user multiple-input multiple-output, MU-MIMO, data transmission method, wherein the method comprises: obtaining, by a base station, a first precoding matrix indicator, PMI, of first user equipment, UE, wherein a first rank of the first UE is 1; obtaining, by the base station, a second PMI of second UE, wherein a second rank of the second UE is 1, and a weighted value corresponding to the first PMI and a weighted value corresponding to the second PMI form a weighted value corresponding to a third PMI whose rank is 2; separately performing, by the base station by using the third PMI and a same time-frequency resource, data transmission with the first UE and the second UE that are paired, wherein a pairing gain of the first UE and the second UE is greater than a preset threshold, wherein the pairing gain of the first UE and the second UE is calculated by performing the following operation: subtracting a scheduling priority of the first UE before pairing from a sum of a scheduling priority of the first UE after pairing and a scheduling priority of the second UE after pairing, wherein the scheduling priority of the first UE after pairing is obtained after spectral efficiency corresponding to a modulation and coding scheme, MCS, of the first UE after pairing is divided by a throughput of the first UE after pairing; the scheduling priority of the second UE after pairing is obtained after spectral efficiency corresponding to an MCS of the second UE after pairing is divided by a throughput of the second UE after pairing; and the scheduling priority of the first UE before pairing is obtained after spectral efficiency corresponding to an MCS of the first UE before pairing is divided by a throughput of the first UE before pairing, and wherein the MCS of the first UE after pairing is obtained by performing the following operations: converting a channel quality indicator, CQI, reported by the first UE into a signal-to-noise ratio corresponding to the first UE; reducing the signal-to-noise ratio of the first UE by 3 dB, and then converting the signal-to-noise ratio into a temporary MCS of the first UE; and adding the temporary MCS of the first UE and a first CQI adjustment amount, and using a sum as the MCS of the first UE after pairing; and the MCS of the second UE after pairing is obtained by performing the following operations: converting a channel quality indicator CQI reported by the second UE into a signal-to-noise ratio corresponding to the second UE; reducing the signal-to-noise ratio of the second UE by 3 dB, and then converting the signal-to-noise ratio into a temporary MCS of the second UE; and adding the temporary MCS of the second UE and a second CQI adjustment amount, and using a sum as the MCS of the second UE after pairing. obtaining, by a base station, a first precoding matrix indicator, PMI, of first user equipment, UE, wherein a first rank of the first UE is 1; obtaining, by the base station, a second PMI of second UE, wherein a second rank of the second UE is 1, and a weighted value corresponding to the first PMI and a weighted value corresponding to the second PMI form a weighted value corresponding to a third PMI whose rank is 2; separately performing, by the base station by using the third PMI and a same time-frequency resource, data transmission with the first UE and the second UE that are paired, wherein a pairing gain of the first UE and the second UE is greater than a preset threshold, wherein the pairing gain of the first UE and the second UE is calculated by performing the following operation: subtracting a scheduling priority of the first UE before pairing from a sum of a scheduling priority of the first UE after pairing and a scheduling priority of the second UE after pairing, wherein the scheduling priority of the first UE after pairing is obtained after spectral efficiency corresponding to a modulation and coding scheme, MCS, of the first UE after pairing is divided by a throughput of the first UE after pairing; the scheduling priority of the second UE after pairing is obtained after spectral efficiency corresponding to an MCS of the second UE after pairing is divided by a throughput of the second UE after pairing; and the scheduling priority of the first UE before pairing is obtained after spectral efficiency corresponding to an MCS of the first UE before pairing is divided by a throughput of the first UE before pairing, and wherein the MCS of the first UE after pairing is obtained by performing the following operations: converting a channel quality indicator, CQI, reported by the first UE into a signal-to-noise ratio corresponding to the first UE; reducing the signal-to-noise ratio of the first UE by 3 dB, and then converting the signal-to-noise ratio into a temporary MCS of the first UE; and adding the temporary MCS of the first UE and a first CQI adjustment amount, and using a sum as the MCS of the first UE after pairing; and the MCS of the second UE after pairing is obtained by performing the following operations: converting a channel quality indicator CQI reported by the second UE into a signal-to-noise ratio corresponding to the second UE; reducing the signal-to-noise ratio of the second UE by 3 dB, and then converting the signal-to-noise ratio into a temporary MCS of the second UE; and adding the temporary MCS of the second UE and a second CQI adjustment amount, and using a sum as the MCS of the second UE after pairing.