The so-called azoospermia refers to three consecutive semen centrifugation microscopic examination did not see sperm, and at the same time need to exclude the ejaculation and retrograde ejaculation before diagnosis, is an extreme case of male infertility, the incidence of which accounted for about 8 ~ 10% of infertile men. The incidence of this condition is about 8%~10% of infertile men. At present, it is often categorized into obstructive and non-obstructive azoospermia. Obstructive azoospermia, the obstruction here refers to the obstruction of the reproductive tract, the channel through which sperm are produced and expelled from the body. The obstruction prevents the sperm from reaching the body, while a large number of sperm are present at the distal end of the obstruction. Common clinical sites of obstruction include the epididymis, the inguinal segment of the vas deferens, and the ejaculatory ducts. These patients often have good spermatogenic function, often due to obstruction of the lumen caused by previous reproductive tract infections, such as epididymitis, epididymal tuberculosis, gonorrhea, etc. or inguinal surgery damaging the epididymis/vas deferens, and of course, obstruction caused by vasectomy. Some men who have had children are tested and found to have no sperm, mostly due to obstruction caused by infections in the reproductive tract after childbearing, resulting in secondary azoospermia. Congenital bilateral absence of the vas deferens, on the other hand, is a special category that is often accompanied by spermatogonial dysplasia or absence of the seminal vesicles. Non-obstructive azoospermia is a type of hypospadias that excludes the obstruction factors mentioned above, and this type of patients cannot produce sperms or only produces a very small amount of sperms, resulting in no sperms being found in the semen. It is usually caused by either congenital or acquired factors. Common congenital factors include congenital testicular hypoplasia (Kirschner’s syndrome), cryptorchidism, and support cell only syndrome. Common congenital factors include congenital hypospadias (Kirschner’s syndrome), cryptorchidism, and support cell only syndrome. Acquired factors include environmental pollution, prolonged exposure to toxins such as lead or benzene (e.g., from drivers and remodelers), testicular inflammation due to mumps, and damage to spermatogonia caused by prolonged use of cottonseed oil. Doctors make the initial diagnosis of this disease by taking a history, physical examination, semen parameters, seminal plasma biochemistry, blood sex hormone tests, ultrasound, and chromosome testing. Based on these tests, the spermatogenic function of the testes is evaluated, rather than simply the presence or absence of sperm in the semen. In addition to this, unilateral testicular volume is generally considered.