Syphilis can recur even after it has turned negative. Syphilis is prone to recurrence in the case of low body resistance and low immune function, therefore, RPR titer test should be performed, and only if it is consistently negative is it considered cured, clinical symptoms disappear, and syphilis RPR test is consistently negative, and it should be observed for two years. Syphilis is easily cured by standardized treatment with long-acting penicillin according to the course of treatment, 80%-90% of syphilis can be cured, and the cost of treatment is also very low. By testing the syphilis titer, if the RPR titer is consistently negative and the systemic symptoms disappear, it should be considered cured. If syphilis recurs, it can also be cured by re-treatment with long-acting penicillin. Therefore, syphilis patients should build up confidence and be actively treated.