One [disinfecting principle] uses high intensity UV germicidal lamp, uses 250~270nm (253.7), which has the strongest bactericidal effect, as the bactericidal factor, which mainly binds the adjacent thymine bond on a DHA chain to form dimer by acting on DHA,. This dimer becomes a special chain, causing the microbial DHA to lose its transformation ability and die. Indoor air circulates through the sterilizing chamber under the action of the fan to achieve the disinfection purpose. 2 [scope of application] 1, air disinfection of class II environment in medical institutions. 2, pharmaceutical factory, sanitary products factory, food processing factory and ballroom, theater and other public places air disinfection. 3, business office, conference room, reception room, hotel, kindergarten air disinfection. The relative temperature of: a) under normal working conditions: 5 ℃ ~ 40 ℃; b) relative humidity: ≤ 80%; c) atmospheric pressure: 86 KPA / 106 KPA; D) Power supply: single phase AC voltage: 220 V ±22 V frequency: 50 Hz ±1 Hz.