The variation of the acoustic characteristics of gas voice is analyzed and researched. The fundamental frequency, intensity, formant and spectrogram of the gas voice and normal voice are extracted, and the differences between the two states are analyzed. At the same time, the differences of acoustic characteristics are compared and analyzed according to the similarity of auditory characteristics between the modified fundamental speech and the gas modified speech. The results show that the characteristic parameters of gas voice change in different degrees and the difference between different individuals is greater than their own differences. The formant values of different speakers are similar, so they do not have individual differences, and cannot be used as the basis of speaker identification.