Abstract：This paper presents a ventilation intelligent control system of mining driving face based on frequencies change technique and pulsating ventilation technique．This system call analyse the gas concentration signal from the gas sensor and make a judgement to the environment of mining driving face．Control the rotate speed of the auxiliary fan in real—time．In order to realize the ventilation intelligent control of mining driving face．When the gas gushes instantly．The system gives out a sound—light alarm and the rotate speed of the auxiliary fan will be accelerated，so the gas concentration will be diluted immediately．The production safety of the mining driving face can be insured．
Keywords：auxiliary fan，gas，PLC，intelligent control，pulsating ventilation
