Objective To study the clinical effect of Bukoubuxu Decoction on ulcerative colitis and its regulating effect on inflammatory mediators and immune function. Methods 100 patients with ulcerative colitis admitted to our hospital from April 2019 to July 2021 were randomly divided into the control group (n=50) and the observation group (n=50). The control group was given mesalazine sustained-release tablets and Bifidobacterium orally, mesalazine suppository rectally, alanyl glutamine injection (Domonte) and compound amino acid injection intravenously for 2 weeks. On the basis of observation and control group, Bukoubuxu Decoction was given once a day, 400mL of soup, twice in the morning and evening, for 2 months.The levels of D- lactic acid in plasma and interleukin-10(IL-10), IL-6 and tumor necrosis factor (TNF-α) in serum were measured by enzyme-linked immunosorbent assay before and after treatment respectively. The levels of fructose and Gan Lu alcohol in urine samples and lactulose/mannitol value (L/M value) were determined by HPLC. Evaluated the clinical efficacy and TCM syndrome score of patients. Evaluated the intestinal mucosa of patients. The level of MUC1 in patients' serum was determined by enzyme-linked immunosorbent assay (ELISA), and the level of MCP1 in patients' serum was determined by enzyme-linked immunosorbent assay (ELISA) and double antibody sandwich method. Results The total effective rates of clinical treatment in the observation group and the control group were 94.00% and 76.00% respectively (P＜0.05). After treatment, the TCM symptom score, D- lactic acid and urine L/M levels, IL-6, IL-10 and TNF-α levels, Geboes index, serum MUC1 and MCP-1 levels in the observation group were significantly lower than those in the control group (P＜0.05).Conclusion Bukoubuxu Decoction has remarkable clinical effect in treating mild-moderate ulcerative colitis, which can significantly improve the inflammatory reaction of patients and increase the immune function