Mitochondrial fusion protein (Mfn) 2 is a transmembrane protein located on the surface of mitochondrial outer membrane (OMM) and endoplasmic reticulum, and has the activity of guanosine triphosphatase. Mfn2 is the key molecule that maintains mitochondrial fusion/fission dynamics, and also the main protein that regulates mitochondrial morphology, energy supply, cell proliferation and death. This article reviews the role of abnormal Mfn2 expression in neuronal development, neurological damage and neurotoxicity by affecting mitochondrial fusion/fission kinetics, and the involvement of mitochondrial fusion/fission abnormalities in developmental neurotoxicity and perioperative cognitive disorder induced by general anesthetic, so as to provide direction for its research in the field of anesthesia.