A dynamic model of ball bearing-offset disk rotor system with whirling-swing coupled vibration is presented, in which the rotor disk offset and disk swing vibration are concerned, in the model of ball bearing, the clearance of bearing, nonlinear Hertzian contact force between balls and races and the varying compliance vibration are considered. Numerical methods are adopted to solve and compare the dynamic response of the system under different disk offset whether considering the disk swing vibration or not. Effects of bearing clearance variation on the dynamic performance of the model under different rotor disk offset are investigated. It is shown that the nonlinear dynamic response of the offset disk rotor system enhances obviously when rotor disk swing vibration is considered. The system contains diverse frequency components under different rotor disk offset even though working at the same speed. As rotor disk offset increasing, the sensitivity of critical speed to bearing clearance variation improves.