Objective To study the clinical efficacy of Guizhi Fuling capsules combined with metformin in patients with polycystic ovary syndrome （PCOS） and insulin resistance. Methods A total of 108 patients with PCOS and insulin resistance admitted to Jiangnan Hospital Affiliated to Zhejiang University of Traditional Chinese Medicine from July 2021 to May 2024 were selected and divided into study group and control group according to the random number table method，with 54 cases in each group. The control group was treated with metformin，and the study group was combined with Guizhi Poria capsule on this basis. The clinical efficacy， estrogen and sex hormone levels and pregnancy-related indicators before and after treatment were compared between the two groups. Results （1） The improvement rate of menstrual disorders，clinical symptoms，and return to normal sex hormone levels in the study group were significantly higher than those in the control group [97.67% （42/43） vs. 80.95% （34/42），92.59% （50/54） vs. 77.78% （42/54），94.44% （51/54） vs. 79.63% （43/54），all P<0.05]. （2） After treatment，the normal range rate of progesterone，testosterone and estradiol in the study group was significantly higher than that in the control group [83.33% （45/54） vs. 55.56% （30/54），88.89% （48/54） vs. 53.70% （29/54），85.19% （46/54） vs. 59.26% （32/54），P<0.05]. （3） The menstrual recovery rate，ovulation rate and pregnancy rate of the study group were significantly higher than those of the control group [98.15% （53/54） vs. 62.96% （34/54），81.48% （44/54） vs. 51.85% （28/54），48.15% （26/54） vs. 14.81% （8/54） （P<0.05）. Conclusion Guizhi Fuling capsule combined with metformin in the treatment of PCOS and insulin resistance can further improve the efficacy， regulate estrogen secretion and increase pregnancy rate.