A method for reducing intermodulation interference, comprising: performing, by a base station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal; and cancelling, by the base station, according to the first intermodulation interference signal, intermodulation interference generated by the M downlink transmit signals in an uplink receive signal, wherein M is an integer greater than or equal to 2, and the M downlink transmit signals are M baseband signals that are transmitted on M carriers and that are not combined, characterized in that the performing, by a base station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal comprises: acquiring, by the base station, M sampling points that respectively correspond to the M downlink transmit signals at a first moment; determining, by the base station, a component element set according to the M sampling points, wherein component elements comprised in the component element set are the M sampling points and conjugates of the M sampling points; determining, by the base station, according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements and N is a positive integer; determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components. performing, by a base station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal; and cancelling, by the base station, according to the first intermodulation interference signal, intermodulation interference generated by the M downlink transmit signals in an uplink receive signal, wherein M is an integer greater than or equal to 2, and the M downlink transmit signals are M baseband signals that are transmitted on M carriers and that are not combined, characterized in that the performing, by a base station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal comprises: acquiring, by the base station, M sampling points that respectively correspond to the M downlink transmit signals at a first moment; determining, by the base station, a component element set according to the M sampling points, wherein component elements comprised in the component element set are the M sampling points and conjugates of the M sampling points; determining, by the base station, according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements and N is a positive integer; determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components. acquiring, by the base station, M sampling points that respectively correspond to the M downlink transmit signals at a first moment; determining, by the base station, a component element set according to the M sampling points, wherein component elements comprised in the component element set are the M sampling points and conjugates of the M sampling points; determining, by the base station, according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements and N is a positive integer; determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components.