Liuzhuang Mine is a concealed coalfield covered by thick loose layer, the southern part of the minefield is developed with a tectonic belt composed of reverse faults F1, F1-1 and F1-2. The upper plate is Cambrian Limestone, purple mudstone and Permian coal-bearing strata, the lower plate is 13-1 coal and the following main coal-bearing sections. The nappe structure with safety coal pillars covers a large amount of coal resources. In response to this situation, through the "integrated exploration, scientific analysis, effect verification, safety evaluation" four-in-one prevention and control of water technology system, the safe mining of coal pillars in the underlying coal seam under the nappe structure belt was realized, and a large amount of coal resources were liberated, with good economic and social benefits.