A multiple-input multiple-output MIMO detection method for a transmit signal, comprising: acquiring, by a receiver, an original channel matrix according to a channel response between a receive antenna and a transmit antenna; removing one group of column vectors from the original channel matrix to generate a corresponding first channel matrix; multiplying a conjugate transpose matrix of a first matrix by the first channel matrix to obtain an equivalent channel matrix, and multiplying the conjugate transpose matrix of the first matrix by an original received signal vector to obtain an equivalent received signal vector, wherein the first matrix comprises a singular vector corresponding to singular value 0 of a conjugate transpose matrix of the first channel matrix, and the original received signal vector is obtained by using the receive antenna; calculating a Euclidean distance between the equivalent received signal vector and a first vector to obtain a Euclidean distance set, wherein the first vector is obtained by multiplying the equivalent channel matrix by a first transmit signal vector, and the first transmit signal vector is an element in a first transmit signal vector set that comprises a symbol of constellation modulation performed on the transmit signal; selecting at least one first transmit signal vector corresponding to at least one Euclidean distance in the Euclidean distance set, or selecting a first transmit signal vector corresponding to a Euclidean distance less than a first distance threshold, so as to constitute a selected first transmit signal vector set; and after each group of column vectors is removed from the original channel matrix to generate a corresponding first channel matrix, and a corresponding selected first transmit signal vector set is acquired by using the first channel matrix, randomly selecting one vector from each first transmit signal vector set, and combining these selected vectors into a second transmit signal vector, so as to constitute a second transmit signal vector set, and detecting a transmit signal vector according to the original received signal vector, the original channel matrix, the second transmit signal vector, and the second transmit signal vector set. acquiring, by a receiver, an original channel matrix according to a channel response between a receive antenna and a transmit antenna; removing one group of column vectors from the original channel matrix to generate a corresponding first channel matrix; multiplying a conjugate transpose matrix of a first matrix by the first channel matrix to obtain an equivalent channel matrix, and multiplying the conjugate transpose matrix of the first matrix by an original received signal vector to obtain an equivalent received signal vector, wherein the first matrix comprises a singular vector corresponding to singular value 0 of a conjugate transpose matrix of the first channel matrix, and the original received signal vector is obtained by using the receive antenna; calculating a Euclidean distance between the equivalent received signal vector and a first vector to obtain a Euclidean distance set, wherein the first vector is obtained by multiplying the equivalent channel matrix by a first transmit signal vector, and the first transmit signal vector is an element in a first transmit signal vector set that comprises a symbol of constellation modulation performed on the transmit signal; selecting at least one first transmit signal vector corresponding to at least one Euclidean distance in the Euclidean distance set, or selecting a first transmit signal vector corresponding to a Euclidean distance less than a first distance threshold, so as to constitute a selected first transmit signal vector set; and after each group of column vectors is removed from the original channel matrix to generate a corresponding first channel matrix, and a corresponding selected first transmit signal vector set is acquired by using the first channel matrix, randomly selecting one vector from each first transmit signal vector set, and combining these selected vectors into a second transmit signal vector, so as to constitute a second transmit signal vector set, and detecting a transmit signal vector according to the original received signal vector, the original channel matrix, the second transmit signal vector, and the second transmit signal vector set.