Abstract: In order to solve the coupled vibration problem in maglev systems,an adaptive notch filter design method is discussed based on the recursive least squares(RLS) method.Superior to the fast Fourier transform(FFT) method,the presented design method needs less design effort and can respond quickly to frequency variance.Simulations show that the filter can get the expected effects.Then,Bode diagram and Nyquist stability theory are used to analyze the influence of the notch filter on the control system stability,and the analysis results indicate that the notch filter can extend the stable control parameter field,and the system performance is improved.Finally,the simulation results are given to testify that the notch filter can suppress the vibration effectively.