In order to investigate the complex characteristics of directional antenna coverage in open?space ramp scenarios of urban rail transit, a methodology combining theoretical modeling and practical scenario analysis was used to investigate signal propagation, ramp environment, and antenna gain characteristics. The results show that the terrain?integrated path loss model yields a measured path loss exponent of 3.01 in the Changsha Maglev ramp environment, which verifies the rationality of the 200?m base station spacing. The proposed ramp–Fresnel zone intrusion analysis model reveals, through coordinate transformation, the leaf?shaped intrusion mechanism of the ramp inflection point on the first Fresnel zone, and quantifies the intrusion interval as 27.7–178.7?m as well as its shrinking tendency with increasing frequency. The constructed roof antenna array pattern correction model quantifies the beamwidth narrowing from 40° to 18.67° and the elevation angle change caused by the metal roof, and indicates that this effect leads to an additional 1.34?dBi reduction in signal strength at 200?m on a 41‰ ramp. It is concluded that the root cause of the communication interruption at Langli Station of the Changsha Maglev line can be accurately diagnosed based on these models. A “phase advance” coverage optimization scheme is consequently proposed, and the fault is completely eliminated after engineering application. A complete theoretical analysis tool and an engineering practice guide are thus provided for wireless coverage planning in open?space ramp scenarios.