Abstract: Objective: The intervention effect of soluble dietary fiber from the outer leaves of Chinese cabbage (CSF) on cyclophosphamide (CPA) induced intestinal barrier damage in mice were studied to provide a theoretical basis for the high-value utilization of CSF resources. Methods: Sixty male ICR mice were randomly divided into five groups: Negative control, model control, and 125, 250, and 500 mg/kg·bw CSF interventions. Structure of the intestinal epithelial tissue, serum and intestinal biochemical indices, tight binding proteins, short chain fatty acids (SCFAs), and intestinal flora were evaluated to determine the protective effect of CSF on intestinal barrier injury in mice. Results: CSF improved the integrity and arrangement of the villi and villus length in the small intestine, as well as the ratio of villus length to crypt depth. The serum levels of lipopolysaccharides (LPS), D-lactate acid (D-LA), and diamine oxidase (DAO) and intestinal permeability were reduced. The expression of zonula occludens-1 (ZO-1), Claudin-1, and Occludin proteins in the small intestinal tissue of model control mice was significantly reversed. The number of goblet cells and intraepithelial lymphocytes in jejunum and ileum were increased, and the expression level of SIgA, β-DF, and LZM were up-regulated. 16S rDNA sequencing was performed to detect the intestinal flora of mice, and it was found that CSF effectively restored the species diversity of the intestinal flora and had a significant regulatory effect on the structure and composition of the intestinal flora. In addition, SCFAs and total SCFAs in the CSF-treated group were significantly or extremely significantly restored. Conclusion: CSF exhibits potential protective effects against CPA-induced intestinal barrier injury in mice through physical, immune, and biological intestinal barriers.