Smallpox is a virulent infectious disease caused by the smallpox virus that was once prevalent worldwide and very contagious, leading to many deaths in the old days when medical care was poor. The pathogen of smallpox is a DNA virus that causes herpes on the skin, causing severe damage to the deeper dermis of the skin. After shedding, deeper scarring will remain for life, which is commonly referred to as pockmarking. In addition to herpes on the skin in batches, there are also some systemic symptoms, such as high fever, and in severe cases, even coma or febrile convulsions, as well as generalized muscle pain, chills, and weakness, and in later stages, there may be serious complications such as pneumonia and sepsis, and even death. Smallpox is the only infectious disease that has been completely eradicated in the world so far, and can be prevented by vaccination with the pox vaccine. Smallpox has been completely eradicated in the natural environment, so there is no longer any need to worry about the occurrence of smallpox.