Abstract: There are cyclical dynamic shocks between the bit body and rocks during the rocks breaking tests. Mean-
while， due to the influence of the test equipments and environmental factors， a lot of noises appear in the drill test
signals， which make it impossible to get accurate test data. Thus， the results often can not truly reflect the charac-
teristics and laws of tests. In this paper， a set of noise removing methods are established on the basis of the floating
threshold algorithm of wavelet transform. After the process and analysis on the practical test data， the methods are
demonstrated to have a good filtering effect on the noise， and are able to improve the accuracy and reliability of the
signal.

Key words: rock breaking test, test signal, noise, wavelet transform, floating threshold