The invention discloses a method of suppressing communication noise of baseband voice signals. At a transmitting end, the baseband voice signal band is divided into two sub bands; low pass filter processing and automatic gain control (AGC) constant amplitude processing are carried out on original voice signals, and the obtained signals are transmitted in the low frequency sub band; an original voice signal waveform envelope is extracted during an AGC process, and envelope signals are obtained and are subjected to frequency modulation and are transmitted in the high frequency sub band; during the AGC constant amplitude processing process, voiced-segment signals are subjected to amplitude compression processing and silent-segment signals are subjected to amplitude expansion processing, the signal amplitudes tend to be consistent, and the dynamic range becomes small; at a receiving end, a voice signal envelope is extracted through bandpass filtering and frequency modulation, and according to the envelope, low pass constant amplitude voice signals are subjected to waveform recovery; and the voice waveform recovery is an AGC inverse process. As the silent-segment signals are compressed and the voiced-segment signals are expanded, the silent-segment noise is thoroughly suppressed, the voiced-segment noise is covered by the voice signals, and good voice intelligibility can be obtained.