After the strong wind passed through the windshield wall along the Lanzhou-Xinjiang high-speed railway, the catenary positive feeder was galloping. In order to analyze the influence of the surface roughness of the stranded wire on the aerodynamic characteristics of the positive feeder under the action of the wake flow of the wind-break wall, a windshield wake wind tunnel experimental device and five wire models with different degrees of surface roughness were established based on fluid mechanics. Due to the large gap between the size of the wire and the overall computing domain, the fluid grid of the overall computing domain is divided into blocks. The fluid simulation software is used to study the aerodynamic characteristics of the forward feeder under different inlet wind speeds. The results show that the lower the surface roughness of the positive feeder is, the more obvious the lift and drag increase. When the inlet wind speed is 1m/s, the basic values of the lift and resistance coefficients of positive feeders with different degrees of surface roughness remain stable. When the inlet wind speed is greater than 5 m/s, the lift and drag coefficients of the positive feeder increase as the surface roughness of the positive feeder decreases. The vortices generated in the tail flow field of positive feeder with different degrees of surface roughness are different, and different small vortices are generated at the concave-convex of the wire. The air flow characteristics near the wall of the positive feeder have changed greatly, and the influence on the aerodynamic characteristics of the wire is obvious.