Occult syphilis refers to untreated syphilis or without adequate and regular treatment, although there are no clinical symptoms, but positive syphilis serologic test. Syphilis is a sexually transmitted disease caused by the syphilis spirochete. It has a slow clinical course and can invade all organs of the body, showing symptoms such as hard chancre, enlarged lymph nodes, syphilis rash and skin and mucous membrane damage. The disease may also remain asymptomatic for many years in a latent state, i.e. latent syphilis. Clinically, the hidden syphilis is usually treated with penicillin drugs, commonly used drugs are benzylpenicillin, procaine aqueous penicillin G, etc. The treatment is usually effective and standardized, and the prognosis is good. Generally, after effective and standardized treatment, the prognosis is good. If the treatment is not timely and fails to receive regular treatment, it may lead to serious development of the disease, or accompanied by serious sequelae. In addition, the early stage of hidden syphilis is also contagious, daily need to pay attention to personal hygiene and safety, and enhance their own immunity. After diagnosis, you should follow the doctor’s instructions to standardize the treatment, scientific use of drugs, do not self-medication.