Abstract: In order to solve the problems confronted by the washery in the operation of its slurry water treatment system,a tailings thickening-pressure filtration on-line automation system is developed through introducing fuzzy control and liquid level control methods and the application of such technologies as PLC control,network communications and sensor-based control system.Filed application shows that the system can work normally and reliably with a remarked control performance,and is easy to maintain,playing an important role for the enhancement of the working efficiency of the slurry water treatment system.