 This paper examines the effects of a rectangular cavity on the aerodynamics and acoustics of a high-speed pantograph. It was found that the cavity produced the most drag and noise when it had rounded and sloped edges, as well as a sloping bottom surface. By rounding and sloping the upstream and downstream surfaces of the cavity, as well as the bottom surface, the drag and noise were reduced by 5.22% and 1.45 dB, respectively. Additionally, the presence of the cavity shielded the lower structure from the wind, reducing the overall drag and noise by 5.22%. This article was authored by Tingting Dong and Tian Li.