The method of electrical detection for leakage of geotechnical films covered with water and soil materials and the method of dual-electrode detection are mostly used for locating leakage of geotechnical films covered with water or soil. The first electrode in the soil or water material placed above the geotechnical film is connected by a power supply. The second electrode is in contact with the conductive material below the geotechnical film. The voltage applied on the geotechnical film produces low current and relatively uniform voltage distribution. The current flowing through the leakage will lead to local anomaly of potential at the leakage position, so as to determine the leakage point.