Abstract: The basic principle of blind source separation was introduced in the paper.Based upon the principle of minimum mutual information,a new method that estimates the separation matrix by independent component analysis was established.The method is named as speedup gradient method.Based on the method developed,the numerical simulation of vibration signal blind source separation was performed.The waveforms of separated signals are identical with source signals.This blind source separation method was applied to multi-sensor signals of a real rotor faults.The results show that the fault characteristics are separated satisfactorily.The real example shows the validity of this method and the practicability for rotors' faults separation.