Polycystic ovary syndrome (PCOS) is a complex and heterogeneous common endocrine disease, and periodontitis is a chronic infectious immune inflammatory disease caused by dental plaque. In recent years, a large number of studies have shown that PCOS and periodontitis may be related, but the pathological mechanism is still unclear. Therefore, this article reviews the correlation between PCOS and periodontitis and the possible biological mechanisms of their mutual influence, in order to provide a theoretical basis for the prevention and treatment of periodontal disease in patients with PCOS.