There are many noise interferences in the vibration process of mechanical systems,especially aviation hydraulic pipeline systems,it is difficult to ensure the accurate analysis of effective vibration signals.In order to solve the problem,an improved nonlinear adaptive Kalman filter was designed by combining nonlinear adaptive algorithm,least square method and traditional Kalman filter.Through simulation,random noise was added into the simulated vibration signal,and the time domain diagram and frequency domain diagram of the vibration signal before and after filtering were compared.The superiority of nonlinear adaptive Kalman filter was verified by comparing the filtering effect with the experimental data.