In this study, the investigators will include PCOS patients who meet the trial criteria, introduce participants to the content of this study, and invite participants to participate. The immune function of peripheral blood samples of PCOS patients was detected by flow cytometry. Participants were further treated with metformin for 6 months and followed up after the intervention. The objective of this study was to investigate immune markers related to the efficacy of metformin in PCOS patients and to predict the efficacy of metformin in PCOS patients using immune function.