Normally erection is normal but not at the critical moment usually refers to male sexual dysfunction, male sexual dysfunction can do basic examination, blood hormone examination and special examination and other items. 1. Basic examination: for patients with sexual dysfunction caused by organic factors, we can understand the pathological changes of the reproductive organs through blood routine, urine routine, blood sugar, blood lipids, liver function, kidney function and other tests. 2. Blood hormone pentameter: luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, thyroid function and other tests can help to determine the endocrine function of reproductive organs and other endocrine functions. 3. Specialized examination: including nighttime genital erection monitoring, genital cavernous injection of vasoactive drug test, genital dual-function ultrasound, genital cavernous manometry, genital cavernous biopsy and so on. Male sexual dysfunction patients should consult the doctor in time for diagnosis and treatment under the doctor’s guidance.