The parallel direct current penetration method with certain advantages for detecting large working faces with high efficiency, long detection range, and obvious characteristics for abnormal reactions, the 15247S large mining face of Jiulong Mine of Baofeng Mining Corporation Ltd. was taken as an example, the parallel direct current penetration method was adopted to find out the water content of the coal and rock layers within a certain depth range of the 15247S working face to ensure the safe mining, the 15247S working face was carried out with detection and evaluation.