Overspeed test is a test in which the powerful centrifugal force generated by high speed rotation,is utilized to preload a high speed rotating workpiece at its normal operating speed or 20% overspeed in order to check whether the workpiece is safe and reliable.In oder to assist the design of an overspeed rotor test machine,the rotor system of the overspeed rotor test bed was simulated by using the finite element method.The vibration characteristics of the machine were analyze comprehensively and the factors that may cause damage to the system were investigated according to the simulation and experiment results,wich provides a theoretical basis for the dynamic analysis of the test,so as to achieve the optimization and upgrading of the design scheme.