The incidence of recurrent spontaneous abortion (RSA) is increasing year by year, which seriously threatens women's reproductive health. With the development of the national triplet policy, the reproductive demand is increasing, but the etiological mechanism of RSA is complicated, and 50% of the causes are still unknown. With the deepening of research, it is found that vitamin D (VD) plays an important role in female reproductive diseases, and RSA patients are generally in a state of VD deficiency. With the decline of VD level, the risk of abortion increases. VD is related to heredity, infection, prethrombotic state, endocrine and immunity, and directly or indirectly participates in the pathogenesis of RSA. In this paper, the etiological mechanism of VD and RSA is reviewed.