Embodiments of the present invention provide a method and an apparatus for eliminating interference among transmission channels of a transmitter. The method includes: generating a compensation parameter according to an output signal of an analog module on a transmission channel to be processed by the transmitter and an input signal of a digital module on each transmission channel among all transmission channels of the transmitter; generating a cancellation signal according to the compensation parameter and an input or output signal of a digital module on another transmission channel except for the transmission channel to be processed; and performing, according to the cancellation signal, interference elimination processing on the transmission channel to be processed. The method and apparatus according to the embodiments of the present invention avoid an increase of a transmitter product size, and improve an effect of eliminating interference among transmission channels.