Polycystic ovary syndrome (PCOS) is a common endocrine metabolic disorder in women of reproductive age. It is often characterized by abnormal menstruation (usually late menstruation or amenorrhea, some of which are characterized by irregular vaginal bleeding), infertility, hyperandrogenism (acne, hirsutism), obesity, and ovarian polycystic manifestations, and may be accompanied by metabolic abnormalities such as insulin resistance and dyslipidemia. Obesity is a common clinical manifestation of PCOS, in fact, more than 50% of women with PCOS are overweight or obese or abdominally obese, and generally have a history of weight gain before the onset of decreased menstrual flow or hyperandrogenic symptoms, thus suggesting the role of obesity in the progression of PCOS pathology, and some studies have also confirmed that maternal obesity may be a high risk factor for future PCOS in female infants. Obesity affects polycystic ovary syndrome from several factors, for example, obesity increases the degree of insulin resistance and hyperinsulinemia, decreases the level of insulin-like growth factors (IGFs), decreases the level of sex hormone-binding proteins, increases the conversion of androgens, and increases blood lipids. In addition to the risk of concomitant coronary heart disease, hyperlipidemia and diabetes, obesity also affects oocyte quality and pregnancy outcome; also during ovulation promotion, the ovarian response to ovulation promotion may be low if concomitant obesity is present, leading to ovulation promotion drug resistance, etc. Therefore, what patients can do for themselves, and must actively insist on doing, is to reduce their weight. Current guidelines for the treatment of PCOS also recommend that weight loss is the first treatment for patients with PCOS with obesity, with an ideal weight loss of at least 5%. How to reduce weight? 1, keep your mouth shut — change bad eating habits, diet control: long-term restriction of calorie intake, choose low-sugar, high-fiber diet; quit smoking, less alcohol, less caffeine; unsaturated fatty acids instead of saturated fatty acids. 2, move the legs —- active exercise: moderate energy-consuming regular physical exercise (30 minutes / day, at least 5 times a week) is the most effective way to reduce weight. 3, not happy, not sad – to reduce mental stress, smooth emotions. At the same time, a regular life, good rest, early to bed and early to rise is also important. In addition, as the family and friends of PCOS patients should give encouragement and support to the patients, so that they can persist in the long term and not make weight rebound.