Objective: To investigate the effect of cereal polyphenols (ferulic acid and caffeic acid) and dietary fiber (arabiNO_xylan and β-glucan) complexes in influencing high-fat diet-induced obesity in mice. Methods: Forty-eight male C57BL/6J mice were randomly divided into a control group(CON)， a cereal polyphenol and dietary fiber complex group (PPDF)， a high-fat chow group (HFD)， and a high-fat chow plus complex group (HFD+PPDF)， and after 18 weeks of ad libitum food intake， the effects of PPDF on obese mice were evaluated based on haematological biochemical and histopathological indices， and the effects of PPDF were analyzed by high-throughput sequencing technology to analyse the changes in colonic flora composition. Results: Compared with the HFD group， mice in the HFD+PPDF group showed significant reductions in body mass increase， liver index， serum alanine transaminase (ALT) and malondialdehyde (MDA) levels by 13.7%， 12.6%， 35.5%， and 23.0%， respectively； and a significant increase in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities by 43.1%， 36.7%， respectively； and glucose tolerance abnormality was significantly improved. PPDF increased the diversity of the gut microbiota of mice on high-fat diet， in which the Ace index and Chao1 index were significantly increased by 30.1% and 30.9%， respectively； and the abundance of Bifidobacterium， Roseburia and Lachnospiraceae_NK4A136_group were significantly increased by 76.6%， 76.6%， 1 727.5%， 315.5% and 315.6%， respectively； while the abundance of Lactobacillus， Romboutsia， Erysipelatoclostridium， Clostridium_sensu_stricto_1， and Blautia were significantly reduced by 68.5%， 90.2%， 61.4%， 75.2%， and 95.6%， respectively. Correlation analysis showed that Bifidobacterium and Akkermansia were significantly negatively correlated with increased body mass， liver index and abnormal glucose tolerance， and significantly positively correlated with antioxidant activity； whereas Lactobacillus， Romboutsia， Erysipelatoclostridium， Clostridium_sensu_stricto_1 and Blautia were inversely correlated with it. Conclusion: PPDF may improve glucose metabolism disorders and prevent obesity by increasing the diversity of gut microbiota and the abundance of beneficial bacteria in mice.