During the start-stop process of high-speed bearing rotor system,the high-precision spectrum analysis method of stationary and non-stationary signals was studied.The frequency,amplitude and phase of stationary signal spectrum analysis were corrected by proportional correction method.A method for transforming non-stationary signals in the t -time domain into stationary signals in the t2 time domain was studied.Based on the stationary signal,the spectral analysis was performed using the proportional correction method,finally the results were returned to the t -time domain to obtain the frequency domain parameters at a certain moment.The simulation analysis demonstrates the method can accurately extract both the spectral characteristics of the stationary signal and the frequency,amplitude,and phase of the non-stationary signal at a specific time,by which the problem of spectral analysis feature extraction of the fast-changing process of the bearing rotor system is effectively solved.It provides a new idea for the analysis of dynamic characteristics.