GIL (Gas Insulated Line), known for its advantages such as high transmission capacity, flexible spatial arrangement, high reliability, long service life, and minimal environmental impact, has been widely used in various large hydropower stations. Existing online partial discharge monitoring devices and offline localization systems face the challenge of insufficient localization accuracy when identifying partial discharge in long vertical GIL This paper develops a high-precision, long vertical shaft GIL automatic partial discharge localization device based on the single-channel sampling rate of up to 20 GS/s and multiple channels with adjustable sampling rates for ultra-high-frequency synchronous triggering. Through an automatic threshold-triggering determination algorithm and a noise recognition algorithm, it can reliably capture the ultra-high-frequency original pulse waveform of intermittent partial discharge signals in GIL, achieving automatic localization with an accuracy of within 10 cm. This facilitates precise identification and localization of partial discharges in long vertical shaft GIL systems.