Abstract: In view of problem of big power consumption, low degree of automation, low accuracy and real-time performance existed in traditional and artificial control method of fireproof and extinguishing by even air pressure, an automatic frequency-conversion control system of fireproof and extinguishing by even air pressure was designed, and composition, operation mode， control method and logic implementation process of the system were introduced. The system adopts theory of local dynamic air pressure balance of multilayer goaf flow field, uses method of automatic frequency-conversion to control local ventilator to change pressure of working face according to differential pressure of working face and upper adjacent goaf, so as to reach the purpose of pressure equalizing of working face and ambient, which realizes automatic control of fireproof and extinguishing by even air pressure of interconnected mining working faces of multilayer goaf.