以大跨桥梁中常用的近流线型箱梁断面为研究对象，通过计算流体力学(computational fluid dynamics, CFD)数值模拟方法，对断面流场特性进行分析。并利用Fluent软件对近流线型主梁断面绕流进行数值模拟，得到−6˚~+6˚风攻角范围内风轴坐标下的静力三分力系数，并经后处理软件处理得到±5˚风攻角下桥梁断面的流场分布示意图(包括压强分布图、流速分布图及流线图)。分析结果表明：风攻角为主梁断面三分力系数的影响因素，且随着风攻角的增大，阻力系数先减小后增加，升力系数逐渐增加，扭矩系数逐渐减小。 Taking the nearly streamlined box girder section commonly used in long-span bridges as the re-search object, the flow field characteristics of the section are analyzed through the numerical si-mulation method of computational fluid dynamics (CFD). And use the Fluent software to numeri-cally simulate the flow around the cross-section of the nearly streamlined main girder, and obtain the static mean aerodynamic force coefficient under the wind axis coordinate within the range of −6˚~+6˚ wind attack angle, and the post-processing software processes to obtain ±5˚ Schematic diagram of flow field distribution of bridge section under wind attack angle (including pressure distribution diagram, velocity distribution diagram and streamline diagram). The analysis results show that the wind attack angle is the main factor affecting the mean aerodynamic force coefficient of the beam section, and as the wind attack angle increases, the drag coefficient first decreases and then increases, the lift coefficient gradually increases, and the torque coefficient gradually decreases.