Ultraviolet sterilizer for ward exhaust duct and use method of ultraviolet sterilizer

The invention discloses an ultraviolet sterilizer for a ward exhaust duct and a use method of the ultraviolet sterilizer. The device comprises a first frame, a disinfection assembly and a cleaning assembly, the disinfection assembly is detachably connected to the interior of the first frame, the cleaning assembly is connected to the interior of the disinfection assembly, an arc-shaped groove is formed in a supporting frame, a first ultraviolet lamp is cooperatively connected to the interior of the arc-shaped groove, and the cleaning assembly comprises an electric telescopic rod. An electric telescopic rod is connected to one side of the interior of the arc-shaped groove in an embedded mode, one end of the electric telescopic rod is detachably connected with a vertical rod, and the electric telescopic rod works to drive the vertical rod with one detachably connected end to move left and right, so that the circular ring is driven to move left and right on the surface of the ultraviolet lamp; the top of the vert