This kit adopts double antibody sandwich method and colloidal gold immunochromatography technology. The colloidal gold conjugate of anti-HBsAg antibody is pre-coated to glass cellulose membrane. Anti-HBsAg antibody and anti-mouse IgG antibody are coated on the reaction line and quality control line of nitrate fiber membrane respectively. When testing, if it is the positive sample, HBsAg in the sample can combine with the gold labeled anti-HBsAg antibody to form a complex. Due to the chromatography, the complex moves forward along the strip and then combines with the antibody precoated by the reaction line to form a “gold labeled antibody ~ HBsAg ~ antibody” complex to agglutinate and display color. The nitrate fiber membrane is coated with a quality control line as a control, so when there is a red quality control line and a red reaction line, it is judged as positive. When there is no HBsAg antigen in the sample to be tested, only one red quality control line is judged as negative.