This paper analyzed the modulation feature of cavitation vibration sign al. The numerical value simulation and experiment on features of cavitation vibr ation signals were studied using demodulation and autocorrelation algorithms. It was found that the effect of noise suppression is very good by using autocorrel ation in the time domain, while the modulation characteristic is not clear. The modulation frequency was extracted by the demodulation. If the modulation signal was first processed by using Hilbert envelope before the correlation analysis, the modulation feature can also be extracted.