Before surgery, HIV is a mandatory test. Not only AIDS, but also hepatitis B, syphilis and hepatitis C are infectious diseases that must be checked because they can be transmitted through blood and body fluids. Pre-operative screening for these infectious diseases has several implications: 1) to improve the examination of infectious diseases, so that the doctor can better understand the patient’s condition and better protect the patient during the operation, so as to avoid the patient’s infection during the operation. 2) to learn that the patient has an infectious disease before the operation, when the patient is found to be infected after the operation, it is clear that the patient is not infected during the operation, but is infected before the operation. The patient has been infected before the surgery, which can avoid related medical disputes.