The invention discloses a mounting device for a hanging type 120-type air control valve. The device comprises a mounting seat which comprises a lifting plate, an outer side plate and an inner side plate, the lifting plate, the outer side plate and the inner side plate are connected to form a U shape, the lower end of the mounting seat and a chassis of a vehicle form a floor, the lifting plate is used for mounting the hanging type 120-type air control valve, a first opening is formed in the inner side plate, and two sides of the mounting seat are open; the device further comprises a front protective cover and a rear protective cover which are detachably connected with the mounting seat, wherein the front protective cover and the rear protective cover can block the two open sides of the mounting seat respectively, and clamping hook structures are arranged on the front protective cover and the rear protective cover; the device further comprises locking mechanisms which are arranged on the two sides of the mounting seat, the locking mechanisms are matched with the clamping hook structures, the locking mechanisms can lock the clamping hook structures, and the front protective cover and the rear protective cover are fixed to the mounting seat; the mounting seat, the detachable front protective cover and the detachable rear protective cover are adopted to form a mounting and protecting structure, so that reliable mounting of the hanging type 120-type air control valve can be guaranteed, and the hanging type 120-type air control valve can be conveniently disassembled.