Aiming at the problems such as low efficiency,huge labor intensity,more misoperations of existing relay control way in drainage system of domestic coal mine,the paper introduced an integrated automation system for drainage of coal mine.The system combines with technologies of computer,industrial Ethernet and PLC control,adopts layered structure design method,and adopts (VC++) and configuration software of PLC to design software of main station and substation of the system.It not only realizes automatic drainage with constant water level but also can monitor running conditions of the drainage system centrally, so as to improve security and reliability of the drainage system of coal mine.The actual running result showed the system has stable and reliable performance and higher control precision,which can meet requirements of safe production of coal mine.