Abstract: This paper introduced the principle and method of coal mine transient electromagnetic advanced detection technology,taking the overlying old gob water detection in Pangpangta coal mine 10-702 working face as an example,the advanced detection was carried out by using this technology.On this basis,dredging and draining water project was designed to dredge and drain water in abnormal area,and the accumulation of water flowage was up to 475 800 m³,which effectively eliminated the 5^# gob water above the working face.