Negative oxygen ions themselves carry redundant electrons, and the principle of killing bacteria and viruses is to destroy the molecular protein structure of microorganisms such as bacteria and viruses, causing structural changes or energy transfer, thus killing microorganisms such as bacteria and viruses. Negative oxygen ions in the air come into contact with bacteria, molds and viruses. Because negative oxygen ions themselves carry redundant electrons, they will destroy the structure of molecular protein, causing structural changes (protein polarity inversion) or energy transfer, thus reducing the activity of some bacteria and viruses and dying, and finally sinking to the ground. Moreover, a proper amount of negative oxygen ions is not only harmless to human body, but also beneficial to human health. Therefore, "negative oxygen ion sterilization" is a more environmentally friendly sterilization method than ozone or ultraviolet sterilization.