Hepatitis B is a blood-borne disease, mainly through blood (such as unsafe injection history, etc.), mother-to-child transmission and sexual transmission, skin and mucous membrane breakage transmission also has a certain proportion, such as tattoos, ear piercing, endoscopy, etc. Blood products are now strictly controlled, the possibility of transmission is greatly reduced, irregular transfusion of blood and blood products only when it occurs. Accidental exposure in the work of medical personnel should not be ignored. With the vigorous promotion of hepatitis B vaccine in newborns and the implementation of other mother-to-child interruption measures, mother-to-child transmission has been greatly controlled. HBV infection is not transmitted through the respiratory and digestive tracts, so daily study, work or living contacts, such as sharing the same office (sharing office supplies such as computers), living in the same dormitory, eating in the same restaurant, hugging, shaking hands, sharing toilets, etc., will not result in HBV infection. Epidemiological and experimental studies have not found that hepatitis B can be transmitted by blood-sucking insects, such as mosquitoes and bedbugs bites.