Abstract：The Squeeze Film Damper (SFD) has great importance to reduce the vibration of rotary machines. The work characteristics are different for different SFD. The numerical methods of loop arithmetic and curve intersection methods are compared. Next the dynamic characteristic experiments are researched on a SFD. The experimental condition and the methods are introduced. Tree excitation forces are used and the displacement admittance curves are drawn. And then the results of amplitude-frequency characteristic and phase-frequency characteristic on displacement admittance gotten from calculations are compared to experimental results. On the last the conclusions of practical value have been educed.