Threatened abortion complicated with intrauterine hemorrhage is a common disease during pregnancy. Its pathogenesis is related to an imbalance of the maternal-fetal interface microenvironment and obstruction of uterine spiral artery remodeling. Trophoblast cells compose the outermost layer of the maternal-fetal interface microenvironment. Their proliferation, migration, and invasion are closely related to normal pregnancy. They play an irreplaceable role in immune tolerance and regulation, uterine spiral artery remodeling, and maintenance of the maternal-fetal interface microenvironment. In recent years, trophoblast cells have become the main research focus in autoimmune diseases and other fields. Studies have shown that trophoblast cells play an important role in the diagnosis and treatment of threatened abortion complicated with intrauterine hemorrhage. This article reviews the research progress of trophoblast cells in the treatment of threatened abortion complicated with intrauterine hemorrhage.