Alzheimer disease（ AD） is a neurodegenerative disease with high incidence， which seriously affects people's life quality and brings heavy economic burden. The main pathological features of AD are neurofibrillary tangles caused by abnormal tau phosphorylation and senile plaques formed by abnormal aggregation of amyloid beta protein. Recent studies have found that tau misfolding and aggregation interact with endoplasmic reticulum stress， which plays an important role in the pathological mechanism of AD. Therefore， by reviewing the mechanism of endoplasmic reticulum stress and the pathological mechanism of tau protein in the pathogenesis of AD ， this paper explores the possible relationship between endoplasmic reticulum stress and tau protein， in order to provide new ideas and possibilities for the pathogenesis of AD and the development and treatment of new target drugs.