Surging of ventilator occurred in non operating condition not only would cause instability of whole ventilation system but affect service efficiency of ventilator heavily. Based on double requirements to guarantee stable operation of ventilator and high efficient system, surge early warning method of mine ventilator combining axial displacement with surge boundary line was adopted. According to processing measures after surging of ventilator, surge early warning strategy was also put forward through analysis of formation mechanism and systematic risk of fan surge.