Polycystic ovary syndrome does not cause cancer per se. Polycystic ovary syndrome is a manifestation of ovarian hyperfunction, an endocrine disorder, and a metabolic disorder. Its main pathogenesis is due to the lack of ovulation, elevated androgen levels, and insulin metabolism disorders. The main clinical manifestations include the following: first, scanty menstruation due to anovulation and disorganization of the menstrual cycle without ovulation. The second point, due to the increased level of androgen may lead to hirsutism, acne, etc.. The third point is obesity due to insulin dysfunction. However, if polycystic ovary syndrome is not effectively treated, endometrial atypical hyperplasia or even malignant tumor of endometrium may occur under the long-term stimulation of single estrogen.