For an aerospace high-speed long-shaft rotor system vibration problem, considering different bearing support forms and bearing damping, a high-speed long-shaft rotor system calculation model was established, and the influence law of bearing support forms and bearing damping on the critical speed was studied based on Ansys Workbench. The critical speed of the system with rigid bearing support is much higher than that with flexible bearing support; the critical speed decreases with the increase of damping, especially in the first three orders, and the influence of bearing damping on the critical speed decreases with the higher order. In addition, the harmonic response of the high-speed long-shaft rotor system was analyzed, and the response of the system at different positions was basically the same; the response amplitude of the system increased with the increase of unevenness; under the action of unevenness, the response amplitude of the system showed an increasing trend with the increase of damping when bearing damping was considered.