The nutritional and health benefits of lotus rhizome starch (LRS) were investigated by analyzing its basic composition and studying its antioxidant effect through animal experiments. The results of the composition analysis revealed that LRS primarily consisted of starch (75.40%) and soluble sugar (15.33%)， and contained 36 secondary metabolites including carbohydrates， amino acids， phenols and their derivatives， and flavonoids. Dietary supplementation with LRS for a period of 15-45 days effectively regulated the activities of superoxide dismutase and catalase in male Drosophila (W1118)， while significantly reducing the level of malondialdehyde (P<0.05). Furthermore， the moderate dosage of LRS significantly prolonged the survival time of Drosophila under paraquat stress (P<0.05)， and contributed to a 7.43% increase in maximum lifespan and a 24% improvement in climbing ability after 30 days. Non-targeted metabolomics analysis indicated that the antioxidant effect of LRS may be attributed to its regulation on arginine/proline metabolism， alanine/aspartate/glutamate metabolism， butanoate metabolism， ascorbate/aldarate metabolism， as well as amino acid biosynthesis pathways. The findings imply that moderate intake of LRS can effectively regulate the body's antioxidant function.