Alzheimer’s disease (AD) is a degenerative neurological disorder that can lead to cognitive decline, mental behavior abnormalities, and a reduced ability to undertake daily life activities. Tryptophan is an essential amino acid for the human body and is produced by three main metabolic pathways, namely kynurenine, 5-hydroxytryptamine, and indole derivatives. Influencing the metabolites of tryptophan can ameliorate neuroinflammation in the brain and significantly improve cognitive ability, while the occurrence and development of AD are reduced. In this paper, we review the research literature on the use of tryptophan metabolism intervention in AD in the last 3 years from CNKI, PubMed, and other databases, and summarize its mechanism of action, with a view to providing a reference for further research on anti-AD drugs.