An interference alignment method, comprising: obtaining (41, 61, 81) a channel matrix in a multi-channel communication system; determining (42, 62, 82) a first desired signal and a second desired signal of the multi-channel communication system according to the channel matrix; obtaining (43, 44, 63, 64, 83, 84) precoding vectors and receive vectors; and performing precoding processing on transmit signals by using the precoding vectors and sending the precoded transmit signals; characterized in that the obtaining precoding vectors and receive vectors comprises: determining (43, 63, 83) relative equivalent channel gains of each interference signal corresponding to each first desired signal, and setting relative equivalent channel gains of interference signals corresponding to each second desired signal to zero; and determining (44, 64, 84) the precoding vectors and the receive vectors, according to the channel matrix and the relative equivalent channel gains of the interference signals corresponding to each first desired signal and each second desired signal, so that at a receiver corresponding to the first desired signal, after a first receive signal is filtered by a receive vector corresponding to the first desired signal, a signal formed by superposing interference signals comprised therein has a feature of a lattice constellation pattern, and that at a receiver corresponding to the second desired signal, after a second receive signal is filtered by a receive vector corresponding to the second desired signal, some interference signals comprised therein are canceled, wherein the first receive signal and the second receive signal are the transmit signals sent to the corresponding receivers after precoding processing is performed at transmitters by using corresponding precoding vectors. obtaining (41, 61, 81) a channel matrix in a multi-channel communication system; determining (42, 62, 82) a first desired signal and a second desired signal of the multi-channel communication system according to the channel matrix; obtaining (43, 44, 63, 64, 83, 84) precoding vectors and receive vectors; and performing precoding processing on transmit signals by using the precoding vectors and sending the precoded transmit signals; characterized in that the obtaining precoding vectors and receive vectors comprises: determining (43, 63, 83) relative equivalent channel gains of each interference signal corresponding to each first desired signal, and setting relative equivalent channel gains of interference signals corresponding to each second desired signal to zero; and determining (44, 64, 84) the precoding vectors and the receive vectors, according to the channel matrix and the relative equivalent channel gains of the interference signals corresponding to each first desired signal and each second desired signal, so that at a receiver corresponding to the first desired signal, after a first receive signal is filtered by a receive vector corresponding to the first desired signal, a signal formed by superposing interference signals comprised therein has a feature of a lattice constellation pattern, and that at a receiver corresponding to the second desired signal, after a second receive signal is filtered by a receive vector corresponding to the second desired signal, some interference signals comprised therein are canceled, wherein the first receive signal and the second receive signal are the transmit signals sent to the corresponding receivers after precoding processing is performed at transmitters by using corresponding precoding vectors. determining (43, 63, 83) relative equivalent channel gains of each interference signal corresponding to each first desired signal, and setting relative equivalent channel gains of interference signals corresponding to each second desired signal to zero; and determining (44, 64, 84) the precoding vectors and the receive vectors, according to the channel matrix and the relative equivalent channel gains of the interference signals corresponding to each first desired signal and each second desired signal, so that at a receiver corresponding to the first desired signal, after a first receive signal is filtered by a receive vector corresponding to the first desired signal, a signal formed by superposing interference signals comprised therein has a feature of a lattice constellation pattern, and that at a receiver corresponding to the second desired signal, after a second receive signal is filtered by a receive vector corresponding to the second desired signal, some interference signals comprised therein are canceled, wherein the first receive signal and the second receive signal are the transmit signals sent to the corresponding receivers after precoding processing is performed at transmitters by using corresponding precoding vectors.