Smallpox is a severe infectious disease. Once contacted with patients, almost all of them are infected, and the mortality rate is very high. However, two kinds of people are resistant to smallpox: one is those who recover from smallpox, and the other is those who have nursed smallpox patients. Inspired by this phenomenon, our ancestors pioneered the method of smallpox prevention with human pox vaccination. This method is to wear the clothes of patients with scar paste to normal children, or grind the local dull skin after smallpox healing into fine powder, which can be inhaled by normal children through the nose. Because vaccination of human pox has a certain risk (about 1% infection rate), this method has not been widely used, but its invention is of great significance to inspire people to seek ways to prevent smallpox.