Abstract: The asymmetry of bearing clearance and bearing support exists widely in rotating systems. They are the main influence factors of complex vibration characteristics such as rotor vibration jumping, deviation and backward whirling. In engineering, the complex vibration under their coupling influence is not clear, and the relevant equivalent simulation methods are also imperfect. Therefore, a simulation method for equivalent mechanical properties of asymmetric support structures with bearing clearance is proposed. The problem of the existing method, which is difficult to simulate the asymmetry of bearing clearance and support simultaneously, is solved by the circumferential decomposition of the support structure. The effectiveness of the proposed method was verified by the analysis of a typical engine rotor system. The results showed that when the bearing clearance and the support coexist asymmetrically, frequency separation, vibration jumping and deviation appeared, and the influences of bearing clearance and the support were coupled to each other. The proposed simulation method lays a foundation for the in-depth analysis of the mechanism of such complex vibration problems in engineering.