Abstract: In view of problems of large startup wind resistance and ventilation surge existed in switchover control system without blowing-out of mine main ventilator, a hot standby scheme based on air door opening adjustment of main ventilator was put forward, and an automatic switchover control system without blowing-out of mine main ventilator based on fuzzy control was designed. The system uses PLC as control core, adopts fuzzy control algorithm to analyze working status of main ventilator, does not rely on equation parameter of motor running state, and can automatically select the best output to control two ventilators, so as to realize overall volume stability and complete switchover without blowing-out of mine main ventilator. The application results show that the system has good running robustness, can realize stable operation of the ventilation system in the switchover process of the main ventilator, and eliminate possible dangers of gas accumulation and overrun of original switchover system of main ventilator.