Abstract: In order to solve the problem that the lower coal seam is affected by the upper coal seam water area, it is often necessary to explore the location, scope and water volume of the upper coal seam goaf area, reduce unnecessary drilling engineering, and accurately determine the construction parameters of the upper coal seam drilling, so as to provide reliable geological basic data for the accurate liberation of the mining coal seam. On the basis of visiting relevant personnel who worked in small coal mines and consulting relevant materials and local chronicles left by small coal mines, a geophysical exploration method is proposed, which combines the shaft coal point inference and measurement method, ground transient electromagnetic method and seismic method, to study the location, volume of water and the affected area of water. The results show that this method is suitable for the exploration and treatment of the water accumulation area in the unknown mined-out area.