Abstract: In order to improve safe production level of coal preparation plant, the paper expounded necessity of building gas monitoring and control system in coal preparation plant, introduced problems needing attention in design of gas monitoring and control system of coal preparation plant in details. By comparison with gas monitoring and control system of integrated monitoring and control system of safety production of coal mine used in most coal preparation plants at current, it analyzed feasibility of using gas monitoring and control system of coal preparation plant based on PLC in term of safety, rapidity, feasibility of implementation and economy.