The invention relates to a biomarker for abnormal invasion of trophoblast cells and application thereof. It is proved that miR-181b is generally and differentially expressed in pregnancy-related disease tissue with abnormal trophoblast invasion, and S1PR1 is a direct effect target gene of miR-181b; and the discovery of the influence of a miR-181b-S1PR1 pathway on the molecular mechanism of the invasion ability of trophoblast cells provides new clues and potential intervention targets for the prevention and treatment of pregnancy-related diseases caused by abnormal trophoblast invasion.