Abstract: Kilometer drilling rig in underground coalmine often uses too much water in form of clean and sewage water,which brings a lot of pressure to water supply and drainage. On the basis of technological index of quality of water for this equipment（the content of solid less than or equal to 20 mg / L,p H = 6 ~8）,through study of solid-liquid separation of sewage water from drilling hole and its precise filtration technology,a set of on-site coal slurry processing and clarification system in underground coalmine is developed for recycling,which can complete filter cake loading directly. This technology can not only save water,but also tackle many problems in underground coalmine,such as environment pollution,difficult sewage disposal etc.