Polycystic ovary syndrome (PCOS) is a gynecologic endocrine disorder with complex etiology and pathogenesis. Many women of reproductive age are influencedthis disease due to infertility. The pathogenesis of PCOS remains unclear despite increasing studies in recent years. It is generally accepted that insulin resistance, hyperandrogenism and abnormal follicle development play a pivotal role in PCOS. Gut microbiota becomes a research hotspot in the aspect of infectious, immune and metabolic diseases recently. Previous studies have found that gut microbiota could modulate the synthesis and secretion of insulin, and affect metabolism of androgen and follicle development, providing us a new idea for unravelling the pathogenesis of PCOS. Based on these researches, fecal microbiota transplantation may be a promising treatment in rectifying intestinal microecology imbalance and improving metabolism. This paper reviewed recent research advances in the roles of gut microbiota in the occurrence and development of PCOS.