Hepatitis B surface antigen positive indicates that the body is infected with hepatitis B virus, as long as the infection of hepatitis B virus means infectious. Hepatitis B virus can be transmitted through the following ways: 1, sexual life, hepatitis B virus exists in semen, cervical fluid and other secretions of the reproductive tract, and can be transmitted to each other through sexual contact. 2, mother-to-child transmission, hepatitis B virus can be transmitted to the fetus through the placenta barrier. 3, blood transmission, if you and hepatitis B carriers share razors, pedicure, or do not use disposable tooth extraction tools or acupuncture tools, syringes, etc., these medical devices are not strictly disinfected, you may be able to use them to prevent hepatitis B infection, but also to prevent hepatitis B infection. If you share razors, pedicure knives, or do not use disposable dental extraction tools or acupuncture tools, syringes, etc., which are not strictly sterilized, you may get infected with hepatitis B virus; and hepatitis B virus carriers who donate blood can also infect others.