¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography （¹⁸F-FDG PET/CT） is a brain functional imaging technique used to display increased neuronal glycolytic metabolic activity during brain inflammation. It can display metabolic changes in autoimmune encephalitis at different stages and locations， and some certain subtypes of encephalitis have formed specific imaging patterns. The paper summarized the metabolic patterns of different subtypes of autoimmune encephalitis and their metabolic characteristics at different stages of onset， aiming to provide important evidence and opportunities for their early diagnosis and treatment. It is expected to improve the diagnostic criteria and treatment framework of autoimmune encephalitis， and may become an important prognostic evaluation technology for autoimmune encephalitis in the future.