Abstract: This research aimed to investigate the hypolipidemic and antioxidant effects of fermented rice buckwheat. A high-fat model of Caenorhabditis elegans (C. elegans) was established by high sugar (10 mmol/L) induction. After the treatment of fermented rice buckwheat, its effects on the longevity, motility, egg production, reactive oxygen species (ROS) levels, resistance to oxidative stress, and antioxidant enzyme activity of high-fat C. elegans were determined. At the same time, its effect on the triglyceride and free fatty acid content in high-fat C. elegans were examined. The results showed that the maximum life span of high-fat C. elegans intervened by fermented rice buckwheat significantly increased by 30.90% (P<0.01), significantly increased motility by 28.57% (P<0.01), and increased egg production (P>0.05). Furthermore, fermented rice buckwheat could significantly increase the antioxidant enzyme activity (P<0.01), reduce malondialdehyde content and ROS levels (P<0.01), and significantly enhance their ability to resist oxidative stress (P<0.01). In addition, fermented rice buckwheat could also significantly reduce the triglyceride and free fatty acid content of high-fat C. elegans, respectively, reduced by 56.58% and 130.54% (P<0.01). In summary, fermented rice buckwheat exhibited a lipid-lowering effect by enhancing resistance to oxidative stress, reducing fat deposition, and improving the antioxidant enzyme activity of high-fat C. elegans.