To reduce the waste of okara resources and to investigate the functional activities of fermented okara supernatant (FOS). FOS was prepared from fermented okara with Kluyveromyces marxianus C21 as the fermentation strain. Based on the analysis of the active components of FOS， the antioxidant capacity and in vitro improvement of glycolipid metabolism disorders were evaluated， and the mechanism of FOS was also evaluated. The results showed that the contents of total soluble sugar， free amino acid， and total phenol in FOS were significantly increased compared with those of NFOS (non-fermented okara supernatant) by 13.52%， 507.95%， and 16.67%， respectively， and the total antioxidant capacity was 8.57 μmol Fe2+/mL， which was enhanced by 39.15% compared with that before the fermentation. The experimental results of oleic acid-induced high-fat HepG2 cells showed that the intervention of FOS significantly reduced the lipid droplet number as well as the content of triglyceride (25.39%) and total cholesterol (26.90%)， and increased the glucose consumption (46.77%) and intracellular glycogen (51.29%) content of the cells， in comparison with that of NFOS. Western blot results showed that 400 μg/mL FOS significantly up-regulated the expression of glycolipid metabolism-related proteins， and PPARα， IRS1， and GLUT4 were up-regulated by 30.89%， 127.16%， and 22.84%， respectively， compared with NFOS. Overall， FOS significantly ameliorated oleic acid-induced glycolipid metabolism disorders in HepG2 cells， reducing intracellular lipid accumulation and enhancing cellular glucose uptake by activating the expression of PPARα， IRS1， and GLUT4 proteins. The results showed that FOS has a potential role in preventing and ameliorating obesity-induced hyperlipidemia and type 2 diabetes.