The invention relates to the technical field of electric power equipment, in particular to an electric leakage fault detector based on magnetic field signal analysis for line-to-ground electric leakage faults and a using method of the electric leakage fault detector. After the electric leakage fault of line equipment occurs, an electric leakage protector trips, the electric leakage fault detectoris started, a surrounding magnetic field environment is detected, and a threshold value of the equipment is calibrated; different phases of wires are respectively connected, the electric leakage faultdetector is used for detecting change of the magnetic field environment, and electric leakage wires are determined; and the instrument is used for tracking along an electric leakage wire magnetic field, when the intensity of the electric leakage magnetic field is rapidly reduced, the position of a probe of the electric leakage detector is an electric leakage point. The electric leakage fault detector has the beneficial effects that the electric leakage fault detector based on magnetic field signal analysis is used for receiving and analyzing an electric leakage current magnetic field signal in a single wire, sensitivity and accuracy of the equipment are greatly improved, further frequency spectrum analysis and digital operation are carried out on an antenna receiving signal, and operatorscan locate fault points more accurately and reliably.