Abstract: Following an elaboration on the importance of gas monitoring and control for safety operation in coal mine,the paper presents an introduction to the make-up of the gas monitoring and control system developed for use in Chengzhuang Mine Coal Preparation Plant aw well as the maintenance work involved.After the renovation directed toward the optimum control of the equipment operating in different zones where gas varies in concentration or is prone to accumulate,a gas monitoring and troll system is developed. The realization of real-time monitoring and control of gas in the plant has yield noticeable economic and social benefit for the plant. The successful application of the system is of vital importance for plant safety operation,prevention and control of gas and fire hazards and enhancement of level of management in coal preparation plant.