Objective To investigate the correlation between vaginal microecology and sex hormones in polycystic ovary syndrome(PCOS)patients.Methods A total of 101 patients with PCOS admitted to Xiaolan People′s Hospital of Zhongshan from November 2020 to August 2021 were selected as the research group,and 100 healthy women who underwent gynecological examination during the same period were selected as the control group.The vaginal microecology and serum levels of testosterone(T),follicle-stimulating hormone(FSH),luteinizing hormone(LH),estradiol(E2),progesterone(P)and prolactin(PRL)were compared between the two groups,the relationship between vaginal microecology and sex hormones in PCOS were analyzed.Results The proportion of lactic acid bacteria≥70%,the detection rate of pH 3.8-4.5 and Nugent score in the study group were lower than those in the control group,and the rate of vaginal microecological imbalance was higher than that in the control group,and the differences were statistically significant(P<0.05).There was no significant difference in the serum levels of FSH,LH,PRL and T between PCOS patients with normal and dysregulated vaginal microecology(P>0.05).The levels of serum P and E2 in patients with vaginal microecology disorder were higher than those in patients with normal vaginal microecology,and the differences were statistically significant(P<0.05).Nugent score had no correlation with serum levels of FSH,LH,PRL and T(P>0.05),but was negatively correlated with serum P level,and positively correlated with serum E2 level(P<0.05).Conclusion The status of vaginal microecological imbalance and sex hormone changes existed in patients with PCOS,and the vaginal microecological edge of PCOS patients and some correlation with sex hormones existed in patients,it is possible that hormone changes are involved in the formation of vaginal microecological imbalance in patients.