Thymosin beta-4 (Tβ4), a ubiquitously expressed peptide in mammalian tissues and cells, exerts diverse biological effects in the cardiovascular system. Tβ4 regulates cardiac and vascular development during embryogenesis, maintains stemness characteristics and cellular activity of stem/progenitor cells, induces angiogenesis and vascular maturation, and stabilizes vascular integrity.Exogenous Tβ4 supplementation can regulate immune responses, reduce inflammation, inhibit tissue fibrosis, activate and mobilize myocardial/endothelial progenitor cells for cardiovascular regeneration and repair.These mechanisms collectively enhance functional recovery in ischemic hearts, demonstrating Tβ4's dual regulatory roles in both cardiac and vascular systems. Currently, Tβ4 has entered clinical trials for patients with ST-segment elevation myocardial infarction (STEMI), highlighting its therapeutic potential in ischemic diseases. This review summarizes the structural features and biological functions of Tβ4, focusing on its roles in cardiovascular development and injury repair. We further elucidate its cardioprotective mechanisms to provide a theoretical foundation for advancing Tβ4-based therapeutic strategies.