A micro-role drilling monitoring method was brought forward based on BP neural network, whose input signals were the energy eigenvectors of torque signal by using wavelet packet transform. Furthermore, a kind of micro-role drilling on-line monitoring software system has been constructed by using Matlab software and LabView software. Experiments validated that the rate of checking out micro-drills breakage was very high by using wavelet neural networks, with the characters of high-precision, quick-convergence compared with BP neural network, and the monitoring system has good practical value.