Abstract: The vortex-induced vibration (VIV) of a circular cylinder has been a concern of researchers. Most of the available literature data are about a low Reynolds number or a low mass ratio. Based on the SST turbulence model, a mass-spring-damper system is used to simulate and analyze the vortex-induced vibration process occurred at a high Reynolds number, with a high mass-ratio circular-cylinder as the research object. The upper branch of experiment was simulated through fluid-structure-interaction numerical computation. The curve of maximum amplitude ratio versus reduced velocity is in a good agreement with experimental result. The results show that the SST turbulence model is suitable for the flow problems of boundary layer separation caused by strong adverse pressure gradient. The correctness of the fluid-structure interaction method was proved and can be used on the condition of vortex-induced vibration of structures at high Reynolds numbers.