Amyloid-β(Aβ) is a short peptide generated by sequential cleavage of amyloid precursor protein (APP) by β-secretase and γ-secretase. Aβ primarily accumulates in the brain, forming amyloid plaques, which are one of the main pathological features of Alzheimer's disease (AD). The aggregation of Aβ affects intercellular communication, induces cellular stress responses, and leads to neuronal damage and death. Specific expression and mutations in the APP gene, particularly certain mutations in its coding region, can exacerbate the production and aggregation of Aβ, contributing to an increased risk of early-onset Alzheimer's disease. Therefore, Aβ and its generation pathway are central focuses of research and therapeutic development strategies for Alzheimer's disease.