High-speed airflow in wind tunnel tests usually causes dramatic vibration of ejector structure, which may lead to fatigue and even destruction of the wind tunnel. Therefore, analyzing and solving the flow-induced vibration problem is a tough and indispensable part of the wind tunnel security design. In this paper, taking a kind of two-stage ejector as the study object, multiple numerical simulation methods are adopted in order to carry out research on the analysis technique of the flow-induced vibration characteristics of ejector structure. Firstly, the structural dynamics characteristic is analyzed by using the ejector structural dynamics numerical model, which is built on the basis of finite element method. Secondly, the complex flow phenomenon is explored applying numerical fluid-dynamics model of the inner flow field of the ejector, which is constructed on the basis of finite volume method. Finally, based on the two numerical models above, the vibration response of the ejector structure induced by the high-speed airflow is computed via the fluid-solid coupling technique. The comparison of the simulation results with the actual vibration test indicates that these numerical simulation methods can accurately figure out the rule of flow-induced vibration of ejectors.