Polycystic ovary syndrome（PCOS）is the most common and complex heterogeneous endocrine and metabolic disease，with diverse clinical manifestations involving multi⁃organ and multi⁃system，and being one of the causes of infertility and metabolic disorder in women at childbearing age. PCOS threatens the health of women throughout their lives.There have still been so many debates and unsolved issues about its etiology ，diagnostic criteria，and optimal treatment. It is currently believed that the occurrence of PCOS is jointly caused by genetic and environmental factors. Epigenetics combines these two factors together. Metabolomics reveals the etiology，mecha⁃ nisms，and potential therapeutic targets of PCOS. Gut microbiota explains the gut microbes and their hosts interfere mutually.This article aims to discuss the research progress of PCOS in the aspects of epigenetics，metabolomics and microbiota，hoping to better understandthe pathogenesis andtoprovide a new direction for clinical treatment.