In order to study vortex-induced vibration (VIV) performance of π-shaped composite beams with wind fairing, based on the design scheme of a cable-stayed bridge under construction, the VIV performance of the π-shaped beam under different working conditions was tested through a 1∶50 scale rigid section model free suspension wind tunnel test. A study was conducted on the vibration suppression effect of upper and lower stabilizing plates and combined stabilizing plate measures. Furthermore, SST k- ω turbulence model was used to simulate the flow field characteristics around the original section and the recommended measures of the π-shaped beam section, and the vortex suppression mechanism was explored in conjunction with the vortex evolution diagram of the surrounding flow. The research results indicate that the original cross-section undergoes significant vertical VIV under five different wind attack angles, and the vertical amplitude of the +5° attack angle exceeds the allowable amplitude in the specifications. The setting of a lower central stable plate at the same height as the edge main beam significantly reduces the vortex induced vibration response,the vortex vibration performance of the main beam first increases and then decreases with the increase of the height of the lower central stabilizing plate.