It is not true that it takes only three steps to detect syphilis. Early symptoms of syphilis are rare, making it difficult to detect by self-testing, and some of the symptoms may be similar to those of other diseases, which can be easily overlooked. Therefore, the method of self-testing for syphilis is unreliable and requires professional examination in a hospital. Syphilis is a chronic infectious disease caused by Treponema pallidum (IP), which is mainly transmitted through sexual contact, mother-to-child transmission and blood transmission. The disease is extremely harmful, and can invade all tissues and organs of the body or be transmitted through the placenta, causing stillbirths, miscarriages, preterm births, and foetal transmission of syphilis. The only source of syphilis is the patient with syphilis. TP is present in the patient’s skin lesions, blood, semen, breast milk and saliva. Stage I syphilis manifests itself primarily as a hard chancre and sclerosing lymphadenitis, and there are usually no systemic symptoms. Early initial self-examination is usually unable to detect the presence of syphilis virus, you should promptly go to the hospital, through the examination and combined with the medical history and other circumstances to diagnose. Syphilis is a contagious disease, after diagnosis, should strictly follow the doctor’s instructions to take medication, pay attention to isolation protection, to avoid infecting others.