Hepatitis B virus (HBV) is mainly transmitted through blood (e.g., unsafe injection), mother-to-child and sexual contact. Due to strict HBsAg screening of blood donors, HBV infection caused by blood transfusion or blood products has been less frequent; transmission through broken skin and mucous membranes is mainly caused by the use of medical devices that are not strictly sterilized, invasive diagnostic and surgical operations, unsafe injections, especially drug injection, etc. Other routes such as pedicure, tattoo, earring piercing, accidental exposure of medical personnel at work, sharing of razors and toothbrushes, etc. can also be transmitted. Other routes such as foot trimming, tattooing, earring piercing, accidental exposure of medical personnel at work, sharing razors and toothbrushes, etc. can also be transmitted. Mother-to-child transmission occurs mainly in the perinatal period, mostly due to exposure to the blood and body fluids of HBV-positive mothers during delivery. With the use of hepatitis B vaccine combined with hepatitis B immune globulin (HBIG), mother-to-child transmission has been greatly reduced. People who have unprotected sexual contact with HBV-positive people, especially those with multiple sexual partners, are at increased risk of HBV infection. Epidemiological and experimental studies have not found that HBV can be transmitted by blood-sucking insects (mosquitoes, bedbugs, etc.).