The utility model discloses an used leakance electricity fault detection of transformer substation device, looks voltage sensor has been included, looks voltage signal sampling circuit, phase voltage AD circuit, phase current sensor, phase electric current signal collection circuit, phase electric current AD circuit, the power consumption always leaks current sensor, always leak current sampling circuit, total leakage current AD circuit, the feeder leaks current sensor, the feeder leaks the current sample return circuit, feeder leakage current AD circuit, CPU, keyboard circuit, the communication circuit, data storage circuit, warning circuit, a liquid crystal display, to binding post, the device power, the warning trouble can in time appear when the electric leakage trouble appears in transformer substation institute power consumption, on the storage of measuring data and the data storage circuit, all parametric signal of measuring of CPU institute, alarm signal, each feeder return circuit information are passed through liquid crystal display circuit and are shown, make electric leakage fault detection convenient, swift, accurate more.