Abstract: There is a certain association between reproductive tract infection and maternal-fetal outcome. With the development of microbiome technology, in-depth research in this field is gradually increasing. This paper explored the correlation between pregnancy maternal microbiota and complications and adverse outcomes, and summarized the research progress of its mechanism. The results suggest that maternal microbiota dysbacteriosis increase the risk of multiple pregnancy complications and adverse pregnancy outcomes, but there is limited research on the relative biological mechanisms. It is necessary to understand and study the correlation between pregnancy maternal microbiota and complications and adverse outcomes more deeply, so as to contribute to the health diagnosis, early prevention and intervention of pregnant women and newborns.