The principle of ultraviolet sterilization is to destroy and change the DNA structure of microorganisms through ultraviolet irradiation, so that bacteria can die or not reproduce immediately, so as to achieve the purpose of sterilization. The real bactericidal effect is UVC ultraviolet, because the C-band ultraviolet is easy to be absorbed by the DNA of organisms, especially the ultraviolet of 253.7nm is the best. UV sterilization is a pure physical disinfection method, which has the advantages of simple and convenient, wide spectrum and high efficiency, no secondary pollution, easy management and automation. With the introduction of various new designed UV lamps, the application scope of UV sterilization is also expanding.