Angiogenesis is positively correlated with the survival rate of stroke patients. Therefore, studying factors that initiate and promote angiogenesis after ischemic stroke is crucial for finding novel and effective treatment targets that improve the prognosis of stroke. X‐box binding protein l splicing (XBP1s) plays a positive regulatory role in cell proliferation and angiogenesis. However, the role and mechanism of XBP1s on the proliferation of brain microvascular endothelial cells (BMECs) and angiogenesis after cerebral ischemia remains unclear. In the current study, we investigated the role XBP1s plays in BMEC proliferation and angiogenesis following cerebral ischemia. In this study, the roles of XBP1s on cell survival, apoptosis, cycle migration, and angiogenesis were determined in oxygen‐glucose deprivation (OGD) treated BMECs. The expression of XBP1s in BMECs, which were exposed to OGD at 0, 2, 4, and 6 hr, increased in a time‐dependent manner. The overexpression of XBP1s promoted cell survival, cell cycle, migration, and angiogenesis of BMECs, and inhibited the apoptosis in OGD‐treated BMECs. In addition, the overexpression of XBP1s promoted the expression of cyclin D1, matrix metalloproteinase (MMP‐2), and MMP‐9, but inhibited cleaved Caspase‐3 and cleaved Caspase‐9 expression in OGD‐treated BMECs. The overexpression of XBP1s also promoted the expression of hypoxia‐inducible factor 1‐alpha, vascular endothelial growth factor, phosphatidylinositol‐4,5‐bisphosphate 3‐kinase, p‐AKT, p‐mTOR, p‐GSK3β, and p‐extracellular signal‐regulated kinase1/2 in OGD‐treated BMECs. The effect of XBP1s silencing was opposite to that of XBP1s overexpression. In conclusion, using an in vitro OGD model, we demonstrated that XBP1s may be a promising target for ischemic stroke therapy to maintain BMECs survival and induce angiogenesis.