Abstract: This study aimed to investigate the neuroprotective effect of Xanthoceras sorbifolium oil (XSO) on the Drosophila melanogaster model of Alzheimer's disease (AD) and to explore the underlying mechanism. Aβ42 transgenic flies were randomly divided into five experimental groups: An AD model group and four intervention groups receiving different doses of XSO (5, 10, 20, and 40 g/kg in the culture medium) and a wild-type W1118 male control group. The behavioral indices of Drosophila melanogaster, including lifespan, climbing ability, heat resistance, olfactory memory, and intestinal permeability, were detected. The enzyme-linked immunosorbent assay (ELISA) and the Western blot assay were conducted to measure the expression of β-amyloid protein (Aβ42) in the brain tissues of Drosophila melanogaster. Additionally, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were detected using assay kits. The gut microbiota composition was analyzed using 16S rRNA high-throughput sequencing, followed by bioinformatic analysis. The results showed that compared with the control group, XSO treatment at doses of 5, 10, and 20 g/kg could prolong the lifespan of Drosophila melanogaster, and the 10 g/kg dose exerted the most significant anti-aging effect, increasing average lifespan by 32%. Furthermore, the 10 g/kg dose significantly improved the climbing ability, heat resistance, olfactory memory, and intestinal permeability of Drosophila melanogaster with AD, reduced the expression of Aβ42 in brain tissues, and enhanced the activities of SOD and GSH-Px. Bioinformatics analysis revealed that the 10 g/kg XSO intervention altered the gut microbiota composition, enhancing microbial diversity in the Aβ42 transgenic Drosophila melanogaster. In conclusion, XSO exhibits anti-aging effects, and an appropriate dose of XSO can significantly prolong the lifespan of Drosophila melanogaster. It also exerts a certain neuroprotective effect. These effects may be attributed to alterations in the gut microbiota, including increases richness and diversity in aging Drosophila melanogaster, which helps mitigate β-amyloid deposition and enhances antioxidant defenses.