Objective To explore the efficacy of ethinylestradiol and cyproterone combined with insulin sensitizer in the treatment of polycystic ovary syndrome. Methods A total of 100 patients with polycystic ovary syndrome treated in the Department of Gynecology of the First Invalids Hospital of Guangdong Province from August 2018 to August 2020 were selected as the research object. The patients were divided into control group (n=50) and observation group (n=50). The patients in both groups were given ethinylestradiol cyproterone. In addition, the observation group was treated with insulin sensitizer. The levels of serum sex hormone, anti-Müllerian hormone (AMH), metabolic index level and clinical efficacy (including ovulation, pregnancy, etc.) before treatment and 30 days after treatment were compared. Results Before treatment, the levels of serum sex hormone and AMH had no significant difference between two groups (P>0.05). After treatment, the levels of AMH and serum sex hormone both decreased in two groups, and those in observation group were lower than those in control group (P<0.05). Before treatment, it had no significant difference in metabolic indexes (P>0.05). After treatment, the levels of metabolic indexes in the two groups decreased, and those in observation group were lower than those in control group (P<0.05). The effective rate of the observation group was higher than the control group (P<0.05). Conclusions Using single drug treatment has limitations. The combination of ethinylestradiol cyproterone and insulin sensitizer can reduce insulin metabolism and sex hormone levels, improve the probability of pregnancy, which have a good therapeutic effect.