Abstract: Alzheimer disease (AD) is a neurodegenerative disease with insidious onset. The pathological features of AD are senile plaques formed by the deposition of amyloid-β protein and neurofibrillary tangles formed by abnormal aggregation of Tau protein. Through the use of PET molecular probes specifically targeting Tau protein, noninvasive and accurate detection of AD can be completed, which provides an effective method for early diagnosis, disease progression monitoring, pathogenesis and cognitive function evaluation of AD. Represented by ¹⁸F-AV1451, this review summarizes the clinical research progress of Tau protein PET imaging in AD.