Taking an existing large-span suspension bridge as the engineering background， the influence of the aerodynamic contour of a Π-shaped stiffening girder on the measured wind parameters at the main girder level was studied， and a correction method for the measured wind angle of attack （AOA） was proposed based on the field measurement and Computational Fluid Dynamics （CFD） method. Moreover， the field measurements of wind speeds and AOAs at different measurement points on the Π-shaped stiffening girder were carried out for five months. The distribution of wind parameters along the bridge axis was analyzed， and the wind speeds and the wind AOAs measured by the anemometers on the windward and leeward sides at the stiffening girder level were compared， respectively. Furthermore， the CFD method was utilized to simulate the flow field of the stationary girder to investigate the influence of incoming wind speeds and wind AOAs on the wind parameters measured by the anemometer installed at different positions of the Π-shaped stiffening girder. Additionally， a correction formula for the wind AOAs measured at the windward side of the Π-shaped stiffening girder was proposed based on the numerical simulation. The results show that the measured wind speeds are relatively close within the main span while those are lower at the side span. The wind AOAs measured on the windward side are significantly larger than those on the leeward side of the girder， while the wind speeds are almost the same on both sides. The numerical simulation results of the wind parameters measured on the windward and leeward sides are consistent with the measured results， and the flow around the girder has a specific influence on the wind AOAs within 20 m of the girder. Via the wind AOAs data measured on the windward side， the rational wind AOAs results can be obtained based on the correction method proposed in this study.