Abstract: Objective To discuss the effect of vitamin D （VD） and metformin combined with ethinylestradiol and cyproterone acetate on the pregnancy outcome of patients with polycystic ovary syndrome （PCOS） and VD deficiency at reproductive age. Methods The 160 patients with PCOS and VD deficiency at reproductive age in First Hospital of Qinhuangdao from July 2018 to July 2020 were selected; they were divided into groups A （n=80） and B （n=80） according to the random table. Group A was treated with metformin combined with ethinylestradiol and cyproterone acetate, and group B was treated with VD on this basis. The sex hormone follicle-stimulating hormone （FSH）, luteinizing hormone （LH）, free testosterone （T）, glucose metabolism fasting glucose （FGS）, fasting insulin （FINS）, insulin resistance index （HOMA IR）, 25-hydroxy vitamin D3 （25 （OH） D）, quality of ovum （ovum maturation rate, fertilization rate, high-quality embryo rate） and pregnancy outcome were compared between the two groups. Results The FSH, LH, T, FGS, FINS, HOMA-IR after treatment in group A and group B were better than those before treatment. The FSH, LH, T, FGS, FINS, HOMA-IR after treatment in group B were better than those in group A, the difference was statistically significant （P<0.05）. The ovum maturation rate, fertilization rate, and high-quality embryo rate in group B were higher than those in group A; the differences were statistically significant （P<0.05）. The pregnancy rate of group B was higher than that of group A, and the abortion rate of group B was lower than that of group A, the difference was statistically significant （P<0.05）. Conclusions VD and metformin combined with ethinylestradiol and cyproterone acetate can improve the sex hormones, glucose metabolism, 25 （OH） D levels, and quality of ovum in patients with PCOS and VD deficiency at reproductive age, which may be helpful to improve pregnancy outcome; it's worth for further clinical promotion.