Abstract: In view of problem that it is difficult to extract vibration signal and carry out fault diagnosis of coal mine electromechanical equipment, intrinsically safe mine-used portable vibration recorder was applied to collect vibration signal of shearer cutting unit, and spectrum analysis and Hilbert demodulation technique were used to demodulate fault characteristic frequency of the vibration signal, so as to determine fault location, which provides reliable basis for fault diagnosis and maintenance of shearer.