Tau protein is an important protein that physiologically promotes microtubule assembly and stabilization and is involved in neuronal development, axonal transport and neuronal polarity. In Alzheimer's disease (AD), Tau proteins undergo pathological modifications in which soluble Tau assembles into insoluble filaments, leading to synaptic failure and neurodegenerative lesions. Mitochondria are the most important organelles in neurons and are the main source of energy, providing adenosine triphosphate (ATP) through oxidative phosphorylation to maintain normal neuronal homeostasis and function. A growing body of evidence suggests that mitochondrial dysfunction plays a key role in the pathogenesis of AD. Negative effects on mitochondrial bioenergetics, transport and morphology in neurons lead to synaptic damage and cognitive decline in AD. Tau proteins have been shown to interact with mitochondrial proteins, impairing mitochondrial dynamics, mitochondrial morphology and autophagy, leading to neurotoxicity. This article provides a review of the effects of Tau proteins on mitochondria in AD and the mechanisms of action.