Myocardial infarction is one of the leading causes of death in patients with coronary heart disease worldwide. In the early stage of acute myocardial infarction, percutaneous coronary intervention, coronary artery bypass grafting, drugs and other treatment means can restore the blood supply of ischemic myocardial tissue, save the dying myocardium and reduce the mortality rate of patients. However, after the interruption of myocardial blood supply and the restoration of blood supply within a certain period of time, the original ischemic myocardium may suffer more serious damage than that of ischemia. This phenomenon is called myocardial ischemia-reperfusion injury (MIRI), and its mechanism has not been fully elucidated. In this paper, the research progress of MIRI mechanism in recent years is reviewed, and the pathophysiological mechanism of MIRI is expounded, which will help to develop new therapeutic interventions and provide help for clinical treatment of myocardial infarction.