Ischemic stroke accounts for 60%-80% of stroke and is an important type of stroke. Damage of blood-brain barrier is an important pathological feature of ischemic stroke. Stem cells have shown remarkable potential in the treatment of ischemic stroke. From the perspective of protecting blood-brain barrier, this paper expounds the mechanism of transplantation of bone marrow mesenchymal stem cells, endothelial progenitor cells and oligodendrocyte precursor cells in the treatment of ischemic stroke, involving immune regulation and paracrine pathway.