Syphilis is an infectious disease caused by the syphilis spirochete and is transmitted mainly through sexual contact and blood. 1, the source of syphilis infection is the syphilis patient himself, the patient’s skin breaks, blood, semen, milk and saliva are present in the spirochete. The most common way of transmission is through sexual contact. Untreated patients are highly contagious for 1 to 2 years after infection, and the contagiousness decreases as time increases. After the fourth month of pregnancy, syphilis spirochetes can be transmitted from mother to fetus through the placenta and umbilical vein. 2, other ways are: inputting the blood of patients infected with the disease can be infected; intravenous syringe drug use can also be infected, professional books say a few patients can be infected by kissing, shaking hands, breastfeeding or contact with contaminated clothing, utensils. However, clinical observation of patients’ family members infection rate is obviously much lower than the infection between husband and wife. 3.How to prevent disinfection at home? Syphilis spirochete is an anaerobic microorganism, leaving the body is not easy to survive, available boiling, drying, sunlight, alcohol, carbolic acid and soapy water and other common disinfectants can quickly kill it, 42 degrees 1 to 2 hours syphilis spirochete can also die. However, its cold tolerance, found 4 ℃ can survive 2 to 3 days, -78 ℃ stored for several years is still infectious. Can be targeted treatment disinfection.