Stage III syphilis is difficult to cure. Stage III syphilis is characterized by a late onset, usually 2 years after the onset of the disease, and in some cases even longer. The patient’s symptoms are usually complex, and various internal organs such as skin and mucous membranes, bones, joints, and heart, as well as the nervous system of the brain can be involved. There are relatively few syphilis spirochetes in the body, but the tissue destruction ability is very strong, so it usually causes tissue defects and organ breakage in patients. The antiviral treatment can only control the inflammation, but there is no way to repair the damaged tissues and organs. Therefore, once syphilis is diagnosed, it is recommended that early, regular and adequate treatment be given, and that the patient be seen in a regular hospital, which can generally be completely cured in the early stages.