In order to improve the stability and reliability of the integral centrifugal compressor high-speed gear shaft rotor,the dynamics model of the high-speed shaft rotor is established by the professional analysis software. The influence factors of the impeller and the bearings on the dynamics performance of the rotor is analyzed. Through the measurements of increasing the rotational inertia of the impeller,decreasing the mass of the impeller and the distance of the impeller to the bearing,increasing the bearing span of the gear box,bearing shaft diameter and the bearing stiffness,the first order critical speed of the rotor can be improved. Through the measurements of increasing the rotational inertia of the impeller,decreasing the mass of the impeller and the distance of the impeller to the bearing,decreasing the bearing span of the gearbox and the bearing shaft diameter,increasing the bearing stiffness,the second order critical speed of the rotor can be improved. On the contrary,the first and second order critical speed can be reduced.