As corresponding downtime phenomenon of electromotor appeared in existing power operation network under pressure loss situation, delay protection work of electromotor must be done well to avoid a series of hazard triggered by pressure loss. Based on motor self strating principle and response time setting, combining with characteristics of coal mine ventilator, principle of DZQ electromotor reclosing controller and its practical application in mine ventilator were analyzed deeply, which showed that it could effectively protect the motor and ensure safety of mining production.