Syphilis is a sexually transmitted disease infected by the pale spirochete. Two types of antibodies appear after syphilis spirochete infection of the body, one is specific, IgM, which has an inhibitory effect on live spirochete dynamics when complement is present and under anaerobic conditions, and kills or lyses the spirochete, which protects the organism from reinfection. The other type of non-specific antibody, a mixture of IgA and IgM, can bind non-characteristically to lipid-like antigens in normal biological tissues and has no protective effect on the body. The general titer test is a non-specific antibody to syphilis, which is the criterion for judging the healing of syphilis; a negative test means that it has healed, and the syphilis spirochete-specific antibody is a confirmatory test for diagnosis, and some patients can be positive for life after healing. The results of these two tests should be viewed in conjunction with each other. In the first case, a positive rapid plasma reaction test and a positive antibody to the syphilis spirochete means that the patient is infected with syphilis. In the second case, a negative rapid plasma reaction test and a positive antibody to the syphilis spirochete means that the patient has been infected with syphilis in the past and is carrying it for life even after treatment.