STD is a special disease, with a close relationship with morality and ethics, patients are prone to serious mental burden, and a few non-STD people or cured STD patients have a strong morbid fear, which causes patients with psychological and behavioral abnormalities called STD phobia. Phobias and hypochondrias are often seen in STD clinics. There are many causes of STD phobia, mainly the following aspects: (1) own factors: patients often have quality and personality defects; low knowledge level, lack of general health knowledge, easy to blind terror; (2) social factors: social discrimination and rejection of STD patients and their families; STD prevention and control knowledge publicity and education is not popular, the bad influence of abnormal publicity; (3) medical factors: individual (3) medical factors: over exaggeration of the seriousness of STDs by individual medical personnel, irregular treatment indications; or unserious attitude, lack of respect for patients’ personality and privacy, which aggravates their psychological burden. Clinical manifestations: (1) Psychological abnormalities: high fear of STD, suspicion of having contracted STD, and request for confirmation. They are particularly sensitive to their own minor somatic discomfort and changes or even normal physiological phenomena, and consider them as symptoms or early manifestations of STDs; (2) behavioral abnormalities: mainly high vigilance and avoidance of possible ways to contract STDs, such as not daring to have intercourse with their spouses, using their own washing utensils, repeatedly forcing washing, some seeking medical consultation several times a day, being skeptical or unconvinced of the doctor’s explanation, and resolutely demanding repeated examination and treatment To reduce their mental pressure. Laboratory tests for various STDs were not abnormal. The diagnosis of the disease is mainly based on the medical history and clinical manifestations, physical examination and laboratory tests are not positive for STDs, and psychiatric disorders due to various physical diseases are excluded. The diagnosis of STD phobia must be made carefully, neither the diagnosis and treatment of STD should be delayed by misdiagnosing STD as STD phobia; nor the psychological burden of patients should be increased by misdiagnosing STD phobia as STD. Therefore, it is recommended that patients with STD or suspected STD go to the dermatological STD clinic of the regular hospital for consultation and treatment as early as possible.