PCOS is a common reproductive endocrine disorder and highly associated with abnormal glucose and lipid metabolism, with an incidence of about 5%-21% of women of reproductive age and accounting for 50%-70% of the causes of anovulatory infertility. The 2003 Rotterdam criteria: 1) sporadic ovulation or anovulation 2) clinical manifestations of hyperandrogenism and/or hyperandrogenemia 3) ultrasound manifestations of polycystic ovaries (12 or more follicles of 2-9 mm diameter in one or both ovaries and/or ovarian volume greater than 10 ml). 2 of the above 3 criteria were met and other diseases were excluded. Chinese criteria: one of 1,2,3 is required for suspected PCOS. Confirmation of PCOS excludes (1) hyperandrogenemia caused by congenital adrenal hyperplasia; (2) hypothalamic amenorrhea, meconium, HPRL and other abnormal menstrual diseases; (3) organic diseases causing AUB. After weight loss in obese patients, plasma free fatty acids are reduced, muscle and adipose tissue uptake of glucose is enhanced, insulin binding to receptors is increased, and IR ( insulin resistance) is improved. SHBG increases after weight loss, reducing ovarian androgen synthesis and circulating free testosterone. FSH secretion increases after weight loss and reaches a certain concentration to promote follicular development and eventual ovulation. In obese anovulatory women, weight loss of 5.4-6.4 Kg can restore ovulation. This is because a weight loss of 5.4-6.4 Kg is sufficient to reduce abdominal fat and increase insulin sensitivity. For patients with hyperandrogenemia, cyproterone inhibits the activity of P450 lyase, reduces androgen synthesis, and competes with androgens for binding receptors in target organs, blocking the peripheral effects of androgens, and is the progestin with the strongest anti-androgenic effect at present. For patients with insulin resistance, oral metformin can reduce insulin resistance by reducing hepatic glycogen xenobiogenesis, promoting anaerobic glycolysis, increasing glucose uptake and utilization by peripheral tissues, and improving insulin sensitivity of peripheral tissues. Adverse reactions: gastrointestinal reactions, serious adverse reactions can occur liver and kidney function damage and lactic acidosis. Treatment for 8-12 weeks can significantly improve the endocrine disorders of patients, and in some cases, ovulation and regular menstruation can be restored.