The invention discloses an air-passing valve installation structure. The air-passing valve installation structure comprises a speed reducer, an end cover and an air-passing plug. The end cover is fixed above the speed reducer. An air exhausting passage communicated with the inside of the speed reducer is horizontally arranged in the end cover. An upwards inclined boss is integrally formed outside the end cover, and the inclination angle is beta. The air exhausting passage extends to the outside of the boss. The air-passing plug is detachably connected with an outlet of the air exhausting passage. The air-passing valve installation structure has the advantages and positive effects that after improvement, the air-passing plug is directly installed on the boss of the end cover, the appearance is beautiful, the air-passing valve installation structure is not prone to breaking off, and the manufacturing or use cost is reduced.