Ischemic brain injury is a disease that causes a high rate of mortality and disability worldwide. Cerebral ischemia - reperfusion （ischemia/reperfusion，I/R） injury is a cascade of reactions caused by bloodstream reperfusion in the ischemic and hypoxic area. Mitochondrial dysfunction has long been considered one of the hallmarks of ischemia - reperfusion - induced neuronal death. Mitochondrial metastasis from astrocytes to damaged neurons after cerebral ischemia initiates endogenous neuroprotective mechanisms that provide energy support to neurons. This article analyzes and discusses the research progress of mitochondria in the pathological state of ischemic brain injury，the effect of ischemic brain injury on mitochondrial autophagy and mitochondrial dynamics，introduces mitochondrial immunoregulation and mitochondria - related calcium ion homeostasis，emphasizes the role of mitochondrial metastasis on ischemic brain injury and the pathway and mechanism of mitochondrial metastasis between cells，and highlights the prospect of mitochondria as a treatment for ischemic brain injury.