UHF partial discharge detection through UAV is a new method for substation equipment inspection. By obtaining internal discharge signals of equipment through close to live parts, the effectiveness of defect diagnosis can be improved, solving the problems of “large signal attenuation and blind spots” in conventional detection. Due to the influence of small distance of substation equipment, it is necessary to miniaturize the UAV equipped with UHV partial discharge detection device. In this article, three aspects are improved: small sensors, expansion interfaces, and data processing. By combining laboratory and on-site testing, PRPD-PRPS spectra of three types of discharges, including suspended, tip, and surface discharge, were obtained. The relationship between discharge signals and distance was studied, and the device was verified to have good sensitivity, reliability and convenient operation in substation. This device can provide a reference for the UHF detection method through UAV and expand the intelligent inspection method for partial discharge of power equipment.