Noise reduction hose of fresh air system

The utility model provides a fresh air system noise reduction hose which comprises a noise absorption sponge, a hose body, a protection pad, a U-shaped support, a steel belt, a supporting rod, a mounting base, a clamping bolt, a U-shaped sleeving plate and an assembly connector structure, and the noise absorption sponge is connected to the inner wall of the hose body in an adhesive mode; the protection pad is glued on the outer wall of the hose main body; the U-shaped support is connected to the right side of the lower portion of the outer side of the protection pad in a sleeving mode. The steel belt is connected to the upper portion of the outer wall of the protection pad in a sleeving mode, and meanwhile the lower end of the steel belt is inserted into the U-shaped sleeving plate and fixed through a bolt. One end of the supporting rod is welded to the lower end of the U-shaped support, and the other end of the supporting rod is movably embedded in the middle of the interior of the mounting base. The benefic