If 75% alcohol is used, effective virucide can be achieved in a few minutes. Current guidelines for neocoronavirus pneumonia recommend the use of 75% alcohol for effective virucidal activity, and clinical observations suggest that neocoronaviruses can be effectively killed in a few minutes. Alcohol mainly attacks the fat-soluble envelope of the new coronavirus. Alcohol destroys this envelope and denatures the proteins. By leaving the envelope, the virus has no way to release its genetic material into the body’s cells to infect them. Why does it take 75% alcohol to destroy the new coronavirus? In fact, if the concentration of alcohol is too high, for example, 95% alcohol will not be able to pass through the cell membrane or completely dissolve the cell membrane. Because the concentration is too high, dehydration is too fast and easy to make the protein coagulation into a layer of hard film, alcohol can not penetrate the virus. [Tip] In this article, “new coronary pneumonia, new coronary virus pneumonia” was renamed to “new coronary virus infection” on December 26, 2022, as announced by the National Health Commission.