As the most important immune cell in the central nervous system，microglia play an important role in the inflammatory response involved in ischemic injury and in the process of nerve repair. Under physiological conditions，microglia secrete nutritional factors to provide nutritional support to neurons and participate in the establishment of neural circuits. In cerebral ischemic injury，toll - like receptors on microglia can recognize and engulf necrotic neurons and clear apoptotic neurons；At the same time，microglia also release harmful cytokines， aggravating neuronal damage. When cerebral ischemic injury occurs，microglia are activated into two states，one is the pro - inflammatory phenotype （M1 type）：secretion of IL - 1，IL - 6 and TNF -α ，aggravating the inflammatory response；One is the anti - inflammatory phenotype（ M2 type）：secretes IL - 4，IL - 10 and TGF - β1，inhibits inflammation and promotes tissue repair. After cerebral ischemia，microglia - related pathways such as NF -κ B pathway，TLR\NF -κ B pathway， NLRP3 inflammasome pathway，Notch signaling pathway，p38MAPK signaling pathway etc，may be activated. Therefore，drugs affect the activation of microglia through different mechanisms of action or pathways，which may be a new therapeutic strategy.