Erythromycin can be used to treat syphilis, but the syphilis spirochetes in China are generally resistant to macrolides such as erythromycin, so it is rarely used. Penicillin is currently the drug of choice for the treatment of syphilis. If you are allergic to penicillin or can’t use penicillin because of other reasons, you can consider using tetracyclines (such as doxycycline, etc.), or you can choose ceftriaxone for alternative treatment, and you must combine the actual situation of the patient to choose the medication. Long-acting penicillin is the most effective for syphilis, and no drug resistance has been found so far, so if you are not allergic to penicillin, try to choose long-acting penicillin to treat syphilis, which is safe, effective and affordable. Alternative drugs have the possibility of drug resistance, and the treatment may not always achieve good results. Since our syphilis spirochetes are generally resistant to macrolides, erythromycin must be used to treat syphilis only after ensuring that there is no drug resistance, such as testing for syphilis spirochete resistance-related genes, and clinical and serologic follow-up should be strengthened after treatment.