Hepatitis B surface antigen can be donated after conversion. Hepatitis B surface antigen is the first of the five components of the hepatitis B two-half test. It is a protein, which is equivalent to a layer of clothing on the surface of the hepatitis B virus. Hepatitis B surface antigen negative means no hepatitis B virus. The requirement of donating blood is that one can donate blood when one’s physical condition is in a healthy state, and hepatitis B surface antigen negative indicates that the body has returned to a healthy state and normal people are the same, and relevant examinations will be done routinely before donating blood, and blood can be donated when there is no hepatitis B and other diseases. Patients with Hepatitis B surface antigen can donate blood after further examination and evaluation by the doctor, and then they can donate blood if there is no problem.