Blood transfusions can transmit syphilis, a chronic infectious disease caused by infection with the spirochete syphilis, which has a slow course and is a systemic infection. In the course of the disease, it can invade other organs and tissues, producing adverse symptoms, and when progressive damage to the brain, it can be life-threatening. Syphilis is mainly transmitted through sexual contact, but can also be transmitted through blood transfusions and from mother to child. The blood of syphilis patients usually carries syphilis spirochetes, which can be transmitted through blood transfusion, although there is a syphilis incubation period between the invasion of syphilis spirochetes into the body and the onset of the disease. The ability of syphilis spirochetes to live outside the body is low. If whole blood or red cell blood containing syphilis is kept in a thermostatically controlled refrigerator at 4±2°C, the activity of syphilis spirochetes is generally no more than 3 days, but if blood is transfused within 3 days, it is still contagious. Before collecting or donating blood, tests for syphilis, AIDS and other viruses will be carried out. Blood transfusion in regular hospitals is usually not infected with syphilis, but if transfusion is carried out in hospitals with poorer credentials, the chances of contracting syphilis will be correspondingly higher. If infected with syphilis, antiviral drugs should be used as early as possible, and benzylpenicillin can be injected into the muscle to control syphilis.