The dynamic model of dual-rotor coupling system which included rolling bearing dynamics and rotor dynamics was established.Fine integral method and predict-correct Adams-Bashforth-Moulton multi-step method were used to solve the nonlinear dynamic equations of dual-rotor system.Then the influences of bearing structural parameters on dynamic response of rotors were studied.The result shows:(1)the displacement of rotors can be decreased and the stability of rotors can be improved by reducing radical clearance of inter-shaft bearing

but the slide ratio of cage would increase when the radial clearance decreases

so the radial clearance should be selected properly;the slide ratio of cage would decrease and the displacement of rotors would increase when the rollers of inter-shaft bearing are reduced;(2)the displacement and stability of rotors can be optimized when the groove curvature radius coefficients of rings and radial clearance of supporting bearings are decreased

and the stability of rotor would be improved when the rolling elements of bearings are increased.