Abstract: Vortex-induced vibration (VIV) is a kind of vibration that often occurs in the main girder under low wind speed, which may cause fatigue damage to the main girder or affect driving comfort. In order to study the influence and mechanism of wind attack angle on the VIV characteristics of streamlined box girder, the influence of wind attack angle on the response of VIV, the average and fluctuating wind pressure and the contribution coefficient of local aerodynamic force to VIV were analyzed using the method of synchronous pressure and vibration measurement of segment model. The results show that the amplitude of vortex vibration increases with the increase of wind attack angle. The average pressure coefficient of the upper surface at different wind attack angles is different, which is the largest at an attack angle of - 5°and the smallest at an attack angle of + 5°. When the attack angle is positive, the fluctuating pressure coefficient varies greatly in the downstream area of the upper surface of the main girder and the front end of the inclined web on the windward side of the lower surface. The wind attack angle affects the spatial distribution of the fluctuating pressure coefficient on the surface of the main girder to a certain extent, which may be one of the reasons for the different vortex vibration responses. The wind attack angle has a certain influence on the local aerodynamic contribution coefficient. When the wind attack angle is positive, the aerodynamic force on the surface of the main beam has an enhancement effect on the vortex-induced force.