In order to solve problems that current gas-generation pretreatment system used in coal industry cannot fully meet requirements of mine safety and its automation degree is not high, the paper put forward a design scheme of gas-generation pretreatment system which accords with coal mine safety regulation, and expounded structure, realizing methods of each function part and software design scheme of the system. The system has some innovative designs about structure and control method, namely adding a fire-prevention and explosion-proof unit, adding a separator of gas and water and automatic drainage device in dehumidification part, and using PID controllers to control key links. The actual application showed the system improves output power and generating efficiency of generating units and prolongs running time and life of the units compared with current gas-generation pretreatment system, which has higher safety and reliability.