A mixing module (40) comprises a switching mixer (400), controlled by a switch signal and configured to receive an inputting signal and generate an outputting signal; a modulating unit (402), coupled to the switching mixer (400) and configured to generate the switch signal; wherein a switching frequency of the switch signal is higher than an and is a specific multiple of inputting frequency of the inputting signal. The mixing module (40) controls the switching mixer (400) by using the switch signal which is much higher than the inputting frequency of the inputting signal; oversampling is performed on the inputting signal, so that the spectrum energy of the outputting signal is more concentrated, which can avoid the additional noise due to the introduction of sidelobes or harmonics.