Through the combination method of physical model and numerical model, the hydrodynamic load, structural dynamic characteristics and flow-induced vibration characteristics of a large-span upwelling arch gate were studied systematically. The strong resonance phenomenon and causes of flow-induced vibration of the gate structure are revealed. Aiming at the problem of strong vibration, structural optimization was carried out by reducing the size of the projected area of the inclined plane downstream of the gate and the small cross beam at the bottom of the gate. The results of the optimized field prototype measurement show that the proposed scheme can effectively control the harmful vibration of the gate, which makes the gate run stably, safely and reliably, and the correctness of the physical model test is verified.