The invention relates to an application of an alfuzosin compound in prevention or treatment of Alzheimer's disease and related diseases, and belongs to the technical field of medicines. The alfuzosincompound has the effects of improving mitochondrial metabolism, degrading accumulation of various pathological proteins and improving vascular endothelial cell functions. The invention provides a newpharmaceutical application of the alfuzosin compound. The new pharmaceutical application can provide a new choice for treatment of clinical related diseases. Alfuzosin, an alfuzosin isomers, TZ-md andAZ-md can be beneficially applied to Alzheimer's disease and related complications, such as seeing and hearing impairment, anemia, blood pressure instability, insomnia, depression, limb dysfunction,malnutrition, weakness, dizziness, gait instability and the like, and diseases related to protein accumulation and metabolic disorder, such as Huntington's disease, amyotrophic lateral sclerosis, dementia with Lewis bodies, multi-system atrophy and the like.