Abstract: In view of problem of incorrect operation because that decelerate switch of electric control system of hoist and synchronous switch of backup protection device of hoist all used single tongue tube, a mine-used magnetic proximity switch based on double tongue tubes was designed. Working principle of tongue tube was analyzed, structure, working principle and performances of the proximity switch were introduced in details. The actual application shows that the proximity switch can effectively ensure normal working of decelerate switch of electric control system of hoist and synchronous switch of backup protection device of hoist when unloading coal and materials with characteristics of simple structure, waterproof, explosion-proof, vibration-proof and safe and reliable action performance.