The water quality, characteristics of a coal mine water and the processing requirements were analyzed. After the mine well water has been treated using the process of “regulating early heavy + coagulation and sedimentation + filtration + activated carbon adsorption + biochemistry + ultrafiltration + disinfection”. the primary effluent is reused for the fire sprinkler, supplementary water for production and other water for production under the mine, as well as dust sprinkler on the ground， which water quality indicators meet“water quality standard of fire and sprinkle under the mine (GB50383- 2016)”； The secondary effluent will be discharged after meeting the water quality standard specified in“class III standard in environmental quality standard for surface water (GB3838-2002)”.