The two main tests for syphilis are the syphilis spirochete antigen serologic test and the non-syphilis spirochete antigen serologic test, which is a confirmatory test for syphilis. After syphilis spirochetes invade the body, antibodies to syphilis spirochetes appear in the serum and exist for life, so a positive specific syphilis spirochete antibody means that the patient is now infected with syphilis in the body and may need treatment, or that the patient has been infected with syphilis in the past and has been cured. The non-syphilis spirochete antigen serologic test is a syphilis screening test, and if the result is positive, a confirmatory test must be needed to confirm the diagnosis of syphilis. Because a small number of viral hepatitis, autoimmune diseases, malignant tumors, pregnancy and the elderly, false positives can also occur, and some syphilis-infected patients may also have false negatives if they are co-infected with HIV. Changes in the titer of non-syphilis spirochete antigen serologic tests can be used as an indication for efficacy observation, recurrence and reinfection.