A method for discovering an unexploded ordnance in a target area includes: acquiring first feedback signals respectively corresponding to detection regions, the first feedback signals being first induced electromotive force signals; judging whether there is any abnormal signal in the first feedback signals, if there is the abnormal signal, determining the detection region corresponding to the abnormal signal is an abnormal region; acquiring second feedback signals respectively corresponding to detection sites in the abnormal region, the second feedback signals being magnetic field gradient signals; acquiring third feedback signals respectively corresponding to the detection sites, the third feedback signals being second induced electromotive force signals; acquiring location information of the detection sites; obtaining a feature spatial distribution map of the abnormal region; and judging whether there is any unexploded ordnance in the abnormal region according to the feature spatial distribution map.