The experimental study shows that compared with the WT group, the expression of VEGF in the hippocampi of the 3×Tg AD group mice was significantly decreased, indicating that 3×Tg AD group mice have vascular damage and neovascular regeneration disorders, thus leading to nerve vascular unit damage and brain vascular reserves, poor microcirculation blood supply, and thus cognitive dysfunction, which may be related to the nerve and vascular toxicity of Aβ. This evidence concerns the gene VEGFA and Alzheimer disease.