Abstract: Due to being convenient, fast and sensitive to low resistance target body, Transient Electromagnetic Method (TEM) is applied widely in searching groundwater sources, detecting gobs and karst development zones. The paper, on the basis of briefing TEM principle and method, discusses the application of TEM method in hydrogeological exploration of water-accumulating gob and water-riched areas under complex conditions of different mining areas in China. It has been proved to be successful, achieved excellent geological effects and provides scientific basis for ensuring safe production.