Background　Dexmedetomidine （Dex） is a novel and highly selective alpha-2-adrenergic receptor（α2-AR） agonist with potent sedative， analgesic and sympatholytic properties. Many researches have proven its protective effect against organ ischemia/reperfusion injury（I/RI）.　Objective　By summarizing researches domestic and overseas on the protective mechanism in multiple organ I/RI of Dex， we are trying to provide new ideas for further study.　Content　Dex alleviates the I/RI by decreasing lipid peroxidation， attenuating the inflammatory reactions， inhibiting the apoptosis and protecting erythrocyte deformability.　Trend　The protective mechanism of Dex in the case of I/RI should be further clarified to provide theoretical basis for further clinical application.