<p>In the rotor-bearing system (RBS), the dynamic behaviors of the supporting bearing will be influenced by the changes of vibration interaction between the supporting bearings. When a localized defect occurs in one of the supporting bearings, the abnormal vibration generated by faulty bearing is transmitted to the healthy bearing due to vibration interaction. The raceway of the healthy bearing will generate a new localized fault under this cyclic impact and variation in operating conditions, resulting in a transition from unidirectional to bidirectional vibration interaction. To investigate the dynamic behavior of supporting bearing under both types of vibration interaction, a comprehensive dynamic model of RBS was established by using Lagrange equations. The proposed model was validated through the experimental results, demonstrating that it effectively satisfies with the characteristics of vibration interaction. The results show that the dynamic behavior of healthy bearing is influenced by the faulty bearing due to unidirectional vibration interaction. The healthy bearing undergoes further transformation into a faulty bearing, and its dynamic behavior will enter chaos faster due to the co-variation of rotating speed and defect size under the influence of bidirectional vibration interaction. The sequential occurrence of multiple time-varying factors in the time series will result in significant alterations to the dynamic behavior of the supporting bearing. These results are expected to enhance the comprehension of dynamic behavior in supporting bearings.</p>