Abstract: To solve the safety risks of high-altitude operations caused by the large workload of electrical testing and wiring of high-voltage equipment in substations, a wire assembly (disassembly) device for electrical test of substation high-voltage equipment based on angle conversion has been developed. Through research on transformer manufacturers, the angle between the transformer bushing and the riser with respect to the vertical direction was obtained, and the angle range of the angle adjustment structure was determined. Based on the pulley design, the structural design of the sliding device, manual operating mechanism, and wiring clamp has been completed. Finally, an angle-conversion-based wire assembly (disassembly) device for electrical test of high-voltage equipment in substations was designed and manufactured. The electrical test of measuring the insulation resistance of transformer windings was conducted on-site in a 110 kV substation. The on-site test data results showed that the designed device met the requirements of fast, reliable, and safe wiring for on-site voltage testing, improved the efficiency of on-site high-voltage testing, and ensured the safe and reliable conduct of electrical testing.