Abstract: To reduce the operating pressure of water treatment and decrease the power cost in Maiduo Coal Mine, according the practical character of mine water (mine water contains two part: clean water from the roof coal seam 2 and sewerage from mining), this article appraised the present drain system, checked the draining capacity in main and assistant level, and finally proposed the concept draining clean water and sewerage respectively. This project will decrease the total quantity of drain during mining, play an important role in energy saving, and provide an experience to similar complex hydrological mine.