Abstract:The modal analysis was carried out based on the 3D solid model of the A=0.4 m2 film dryer rotor by the ANSYS software, the first four orders of system inherent frequencies and vibration forms were initially attained, the critical speeds of main shaft were calculated; The harmonic response analysis was carried out based on the modal analysis of the rotor by the Full method, the influence of the eccentricity(c=2.5 mm) and the unbalance mass (m=0.1, 0.2 kg) on the rotor vibration were analyzed, and the bearing stiffness was changed to analyze the inherent frequency and vibration characteristic of the rotor system. the results show that: the eccentricity and the unbalance mass have great influences on the rotor vibration response; the bearing stiffness has a certain effect on the inherent frequency and vibration characteristic of the rotor.