By irradiating bacteria, viruses and other microorganisms with ultraviolet rays, the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in the cells of the microorganisms is destroyed, so that the DNA strands are broken, nucleic acids and proteins cannot be formed, resulting in the death and regeneration of growing cells Sex cells die, so as to achieve the effect of sterilization.