The invention discloses a method for realizing the modulation of different degrees, comprising the following steps that: a modulation indicating bit for indicating the high level demodulation and the low level modulation is received, an input channel of a modulation circuit is regulated according to the modulation indicating bit, the bit data stream inputted in the input channel is modulated withhigh level or low level; the bit data stream after being modulated is outputted. The invention also discloses a device for realizing the modulation of different degrees. The embodiment of the invention realizes the modulation of 16 QAM and QPSK by the same circuit by combing the characteristics of the 16 QAM and the QPSK, uses the reduction method of a digital circuit, downsizes the whole circuitscale, lowers the cost of manufactures and operators and saves resources.