Objective: To investigate the effects of brown rice dietary fiber on lipid metabolism in high-fat diet mice. Methods: Thirty C57BL/6J male mice were selected and randomly divided into control group， high-fat diet group and brown rice dietary fiber group according to body weight， with 10 mice in each group. Body weight was measured and food intake was recorded weekly. At 14 weeks， body fat distribution， blood lipid metabolism related indicators of mice were measured， adipose histological changes in liver and epididymis were observed， and colon contents were collected for intestinal flora and bile acids metabolomics analysis. Results: Brown rice dietary fiber reduced the body weight and inhibited the increase in body weight of high-fat diet mice (P < 0.05)； the levels of triglycerides and lipopolysaccharides in the blood of mice were significantly reduced (P < 0.05). In addition， body fat percentage， epididymal adipocyte size， liver fat volume and vacuole number were all reduced in mice. The results of intestinal flora analysis showed that brown rice dietary fiber intervention increased intestinal Ace and Chao1 indices in high-fat diet mice (P < 0.05). At the phylum level， brown rice dietary fiber increased the relative abundance of Bacteroidota， and decreased Desulfobacterota abundance and the ratio of Firmicutes to Bacteroidota (F/B) (P < 0.05). At the genus level， brown rice dietary fiber promoted the relative abundance of the beneficial bacterium Faecalibaculum and reduced the relative abundance of Romboutsia， Lactobacillus， Enterococcus， and Streptococcus (P < 0.05). Bile acid metabolomics results showed that brown rice dietary fiber increased overall bile acids levels and decreased the ratio of 12?琢-OH to non-12?琢-OH bile acids (P < 0.05). The levels of non-12?琢-OH bile acids such as taurine chenodeoxycholic acid， lithocholic acid， hyodeoxycholic acid， and β-ursodeoxycholic acid were significantly elevated (P < 0.05). Conclusion: Brown rice dietary fiber can effectively improve high-fat diet-induced lipid metabolism disorders by regulating the intestinal flora and non-12?琢-OH bile acids levels in mice.