The invention discloses an electrified device for locating a single-phase earth fault of an electric distribution network. The device is suitable for non-effective neutral grounding electrical networks of 3-60kV. The locating device consists of two parts, i.e. an upper position machine and an lower position machine, wherein the upper position machine is arranged in a transformer substation, is used for measuring and transmitting bus zero-sequence voltage signals, and consists of an A/D, a CPU, a mobile communication module and a GPS module; the lower position machine is a handheld device for carrying out mobile detection on a circuit, is used for measuring zero-sequence current signals and finishing location calculation, and consists of a phase-current measuring device and a locating device; the phase-current measuring device consists of a current transducer, an A/D and a Bluetooth wireless transceiver module, and is used for measuring three-phase current signals; and the locating device consists of a CPU a Bluetooth wireless transceiver module, a mobile communication module and a GPS module, and is used for synthesizing the zero-sequence current signals, receiving zero-sequence voltage signals and finishing location calculation. The invention has mature technology and high reliability.