Abstract: This paper introduces a kind of auxiliary method of monitoring the geological disasters，which uses self-developed infrasonic wave to real-time monitor and warn instrument to collect device signal，then transmits it to a PC software system for data displaying，storing，and inquiring.On this basis and after the data is derived，Matlab language is used to analyze and filter the signal wavelet，and then the discrete Fourier transform is adopted to obtain the signal spectrum diagram.Through the analysis and research on the spectrum diagram，the related information of device were accessed，thus to monitor and warn the geological hazards.By tests，it is found that the system has some advantages as stable running，accurate data，high precise monitoring，and good response.

Key words: Infrasonic wave, Geological disaster, ZedGraph graphical control, Wavelet analysis, Matlab