Syphilis can be transmitted through saliva, but the probability is low. The probability of syphilis being transmitted through saliva is greatly increased if both the person with syphilis and the person with whom the person has contact have wounds in the mouth. If the mucous membranes of the mouth of the person with syphilis and the person in contact with the patient are intact, syphilis is generally not transmitted through saliva because the saliva contains low levels of syphilis spirochetes and the probability of transmission is low. If the syphilis patient’s mouth is broken and bleeding, then the patient’s saliva will be mixed with blood containing more syphilis spirochetes, and the probability of contagion is greatly increased at this time. The main ways of transmission of syphilis are sexually transmitted, mother-to-child transmission and blood transmission, and the probability of transmission through saliva is very low. It is recommended that people who are suspected of having syphilis should seek medical attention in a timely manner, and the doctor will choose the appropriate treatment after clarifying the condition.