Protective sleeve for preventing dust and reducing noise of automobile door lock

The utility model discloses an automobile door lock dustproof noise reduction sheath, which comprises a sheath main body, the outer wall of the sheath main body is fixedly connected with a fixed outer sleeve, a sound insulation layer is arranged between the inner wall of the fixed outer sleeve and the outer wall of the sheath main body, one end of the sheath main body is provided with a connecting end cover, and the other end of the sheath main body is provided with a sound insulation layer. A fixed brush plate is fixedly connected to the side, away from the sheath body, of the connecting end cover, a hard sealing ring and a soft sealing ring are installed on the inner wall of the connecting end cover, a metal clamping sleeve is fixedly connected to the side, close to the sheath body, of the connecting end cover, and two fixed metal sheets are installed on the outer wall of the connecting end cover; and fixing bolts are arranged between the tops and the bottoms of the two fixing metal sheets. According to the