Objective To investigate the effects of MenSCs transplantation on HSP90 expression, ovarian injury repair and reproductive system in PCOS rats. Methods Forty healthy female SD rats were randomly divided into healthy group, model group (PCOS rats), treatment group (model +MenSCs transplantation) and control group (model+metformin). PCOS model was established in model group, and MenSCs suspension was injected 200μL (5×107 PCS /mL) into tail vein of rats for 2W. The control group was given metformin 200 mg·kg-1 intragastric administration for a total of 2W. ELISA was used to test the sex hormone levels. Vaginal smear was used to observe the estrous cycle. Reproductive function related indexes PPARG1, NCOR1 and HDAC3 were detected by RT-PCR. HE staining was used to observe the pathological morphology of ovary. Western blotting was used to detect HSP90. Results The estrous cycle of model group was irregular and shortened (P<0.05). Compared with model group, both treatment group and control group were improved (P<0.05). There were more necrotic follicles and inflammatory cells in model group. Compared with model group, treatment group and control group rats improved. Compared with healthy group, FSH and PPARG1 in model group were decreased, while LH, T, NCOR1 and HDAC3 were increased (P<0.05). Compared with model group, FSH and PPARG1 in treatment group were increased, while LH, T, NCOR1 and HDAC3 were decreased (P<0.05). There was no difference between treatment group and control group (P>0.05). Compared with healthy group, HSP90 protein expression in model group was decreased (P<0.005). Compared with model group, HSP90 protein expression was increased in treatment group (P<0.005). There was no significant difference in HSP90 protein expression between treatment group and control group (P>0.05). Conclusion MenSCs transplantation can improve the reproductive function and ovarian function of PCOS rats, which may affect the level of sex hormones by upregulating the expression of HSP90, thereby improve ovarian injury