The baby bites the father of the big three suns and bleeds, generally not infected, if the baby has a broken mouth there will be the possibility of infection. Clinical transmission of hepatitis B virus generally includes blood transmission, sexual contact transmission, mother-to-child vertical transmission of three kinds of patients with tertiary infection is generally highly infectious, when the baby bites a patient with tertiary infection, if the baby’s oral cavity is not broken, no bleeding, generally will not be infected with the hepatitis B virus, and the baby will be injected with the hepatitis B vaccine and immune globulin to increase the protective effect after birth, generally not infected. It is recommended that people who are negative for hepatitis B surface antigen and surface antibody can increase the protective antibody by injecting hepatitis B vaccine, and need to consult a doctor in time after the suspected infectious behaviors to avoid the adverse consequences under the guidance of the doctor.