Characteristics were studied for the floating-ring squeeze film damper.The dynamic model of a rotor supported on the dampers was established.The coupling effect between the rotor and two layers film of the damper was considered in the model.Characteristics of the rotor system responses and other influence factors were analysed making use of numerical integral method.The results of numerical integral show that the bi-stable characteristics of rotor supported on the dampers can be effectively restrained

and the rotor can steadily run if floating-ring mass is appropriate.The results of numerical integral were validated with the experiments of the rotor supported on dampers.