The male reproductive process includes a series of physiological processes such as spermatogenesis, sperm maturation, sperm expulsion, sperm capacitation, and a series of physiological activities of sperm in the female reproductive tract until fertilization. It is a complex physiological process with many links and under neurological and endocrine regulation. The basic conditions for male fertility: one is to have normal anatomy and physiological functions of the hypothalamus, pituitary gland, testes and accessory gonadal system; the second is to have normal semen output channels; the third is to have normal blood flow and innervation of the reproductive system and to be able to have a normal sexual life. Problems in any of the above links cause male infertility. 1, with normal anatomy and physiological functions of hypothalamus, pituitary gland, testes and accessory gonadal system It refers to the balance and coordination of hypothalamic gonadotropin-releasing hormone, pituitary gonadotropin and testosterone synthesis and secretion; normal development of testes, prostate gland, seminal vesicles and other parts, no abnormal physiological functions caused by infection and other factors, and testes can produce sperm and secrete androgens normally. Problems in any of the above links can cause infertility caused by no sperm, less sperm, reduced sperm vitality or too many deformed sperm. 2, with a normal semen output channel The semen output channel refers to the entire pathway from the varicocele, testicular network, epididymal duct, vas deferens, ejaculatory duct to the urethra, and this channel needs to be unobstructed. In case of congenital abnormal development of the penis and urethra, the ejaculate cannot be ejaculated into the vagina of the woman or all of them, which affects fertility; congenital deficiency of the vas deferens and seminal vesicles prevents sperm from being discharged and leads to infertility; specific and non-specific infections of the epididymis, vas deferens and seminal vesicles cause obstruction of the seminal tract, leading to obstructive spermlessness and infertility. 3, the reproductive system has normal blood flow and innervation, and can carry out normal sexual life It means that the reproductive system is under normal blood flow and innervation to complete the normal erection, intercourse and ejaculation process. In the case of abnormal blood flow, testicular atrophy and varicocele may occur, causing inhibition of spermatogenesis and changes in semen quality, resulting in infertility; in the case of vascular impotence, semen cannot be ejaculated into the vagina of the woman, affecting fertility. In case of abnormal innervation, neurogenic impotence, non-ejaculation and retrograde ejaculation may occur, preventing the ejaculation of semen into the vagina of the female partner and affecting fertility. In addition, in terms of semen, according to WHO (1999), the normal reference standards for semen quality are as follows: semen volume of 2-6 ml in one ejaculation, pH 7.2-8.0, white blood cells less than 1 million/ml, sperm density greater than 20 million/ml, forward-moving sperm (class a sperm + b and sperm) greater than 50% within 60 minutes after ejaculation, normal-form sperm greater than 15% and negative immunoassay. It should be noted that this reference standard is not the absolute limit of male fertility, the fertility of both partners are complementary, when the female partner has strong fertility conditions, the male with semen quality slightly lower than this standard still has the ability to make the female partner conceive.