The invention discloses an ultraviolet sterilization and disinfection device. The device comprises a mirror surface support of a frame structure, a PCB arranged inwards is arranged on the side wall ofthe mirror surface support, UVC LED lamp beads are installed on the PCB, and the UVC LED lamp beads are covered with a lens. The PCB arranged inwards is additionally arranged on the side wall of themirror surface support, and the UVC LED lamp beads are mounted on the PCB, so that the sterilization and disinfection device can be conveniently inserted into the interface of an air duct without influencing normal butt joint between the air ducts, repeated mold opening of an air duct system due to configuration difference is reduced, and the cost is reduced; ultraviolet rays emitted by the UVC LED lamp beads are irradiated to air flowing through the air duct, and DNA or RNA molecular structures in bacteria and viruses are destroyed by short waves of the ultraviolet rays to cause death of growth cells or regeneration cells, so that the effects of sterilization and disinfection are achieved, and sterile air is continuously output; and the lens enables the UVC LEDs to emit light more uniformly through an optical refraction principle, so that the sterilization and disinfection effects are improved. The device is suitable for automobiles.