Abstract: Random noise contained in the mine micro-seismic signal has serious interference to the micro-seismic monitoring and the accurate positioning of the micro-seismic source. According to the previous research and the actual application effects， the paper proposed a new denoising method with the hierarchical adaptive threshold based on the characteristics of mine micro-seismic signals. It adds the layered adaptive factors to the hierarchical threshold. According to the low frequency characteristic of the mine micro-seismic effective signal， the noise signal of the high frequency part is removed greatly by using the layered adaptive factor to improve the signal to noise ratio of the mine micro-seismic signal. And the signal of the low frequency part is maximally kept. The validity and superiority of the method are illustrated by comparing the hierarchical threshold with the real-field micro-seismic data.

Key words: mine micro-seismic signal, wavelet transform, denoising method, adaptive threshold, signal to noise ratio