In order to achieve Guzhuang Mine explosion-proof pressure feeding switch loss protection, ensure the safety of the important equipment operation, increase capacity of permanent magnetic operating mechanism transformation, the spring mechanism was improved by adding relay and rebuilding capacitance. The practice showed that the transformation scheme was simple and feasible. Through the transformation of the switch, the protection of the voltage loss delay of the switch was realized, and the probability of mine power loss and accidents caused by the fluctuation of the power grid was reduced.