Hepatitis B surface antibody quantification is generally used to reflect the amount of antibodies in the body that can protect the body from hepatitis B virus infection, and the higher the antibody quantification, the stronger the protective effect. Hepatitis B surface antibody is one of the two half tests for hepatitis B. Positive hepatitis B surface antibody indicates that the human body has the function of preventing infection of hepatitis B virus. Generally speaking, antibody quantification of more than 10IU/L is defined as positive, and the higher the quantification is, the stronger the protective effect is, and when the quantification of the antibody is more than 100IU/L, it indicates that the protective power is stronger. Clinically, when hepatitis B surface antibody is positive, if hepatitis B surface antigen is negative, it means that the human body has immunity against hepatitis B virus; if core antibody and e antibody are positive at the same time, it means that the human body has been infected with hepatitis B virus in the past. For those who are negative for hepatitis B surface antibody, it is recommended to improve the protection effect by injecting hepatitis B vaccine, and for those who have low quantitative hepatitis B surface antibody, they can take booster injection under the instruction of physician.