Abstract: Tissue repair is essentially a highly coordinated biological process involving multiple systems, and the orderly reconstruction of the vascular network is one of its key components. Previous studies have focused on the regulation of vascular endothelial cells by innate immune cells. In recent years, researchers have discovered that adaptive immune cells play a significant role in tissue repair. However, studies on the interactions between adaptive immune cells and vascular endothelial cells remain limited. Among these, regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis and shaping the tissue repair microenvironment. A deeper understanding of their regulatory effects on vascular endothelial cells will help elucidate how the adaptive immune system regulates vascular reconstruction during tissue repair. In this study, we established a hypoxic cell culture model to simulate the hypoxic microenvironment following injury. We found that the hypoxic environment upregulated HIF-1α expression in Jurkat T cells and promoted FOXP3 expression, resulting in a Treg phenotype. Results from co-culture experiments with vascular endothelial cells indicate that regulatory T cells can significantly enhance the migration and angiogenesis capabilities of vascular endothelial cells. RNA-seq transcriptomic analysis revealed that hypoxic primary Treg cells remodel vascular endothelial cell function by activating signaling pathways such as VEGF. This study demonstrates that Treg cells can promote the reconstruction of vascular networks by vascular endothelial cells in a hypoxic environment, providing new therapeutic targets for immune-vascular synergistic therapy.