Abstract: In order to provide the reference for the coal mine production in the water shortage area, this paper studies the underground drainage treatment technology and equipment. This paper introduces the improvement process of the patent, which is "Swirl coagulation Clarification + Mechanical Filter + Disinfect", and the drainage of the mine enters into the pre settling regulating tank, regulates the water quantity and the water quality, and then enters the core processing unit. A complete set of processing equipment using the PLC+ PC control system to ensure the smooth operation of equipment. The test results show that the Xiaohuigou coal mine water treatment technology is mature and reliable, easy to operate, easy to manage and maintain. Core processing technology and equipment can effectively remove suspended solids, reduce turbidity, water quality has reached a predetermined target. The utility model solves the contradiction that the water shortage affects the production of the small back ditch Xiaohuigou coal mine.