To explore the mechanism of Modified Qingre Shenshi Decoction（清热渗湿汤化裁）regulating TLR4/NF-κB signaling pathway in improving ulcerative colitis.

A total of150 patients with ulcerative colitis admitted to the hospital from January 2021 to January 2024 were selected and divided into control group（75 cases，treated with mesalazine enteric-coated tablets）and observation group（75 cases，treated with Modified Qingre Shenshi Decoction）according to a random number table.The efficacy and adverse reactions of the two groupswere compared.TCM syndrome scores，disease evaluation，serum factor and mRNA expressions of TLR4 and NF-κB in two groups were observed.

After treatment，the total effective rate of the observation group was higher than that of the control group（P<0.05）.Before treatment，the scores of lower abdomen fullness and pain，burning anus，strong anal distension，diarrhea，mucus，pus and blood stool，heavy limbs，chest tightness and fever，dry mouth and bitter mouth and short urine red were not significant between the two groups（P>0.05）.After treatment，the scores of the above symptoms were all lower than those before treatment.In addition，the scores in the observation group were significantly lower than those in the control group（P<0.05）.Before treatment，the scores of Baron endoscopy and mucosal histology were not significant between the two groups（P>0.05）.After treatment，the scores of Baron endoscopy and mucosal histology in the two groups were lower and the scores in the observation group were significantly lower than those in the control group（P<0.05）.Before treatment，the levels of interleukin-1β，tumor necrosis factor-α，endotoxin and D-lactic acid were not significant between the two groups（P>0.05）.After treatment，the levels of interleukin-1β，tumor necrosis factor-α，endotoxin and D-lactic acid in both groups were lower than those before treatment，and the levels in the observation group were significantly lower than those in the control group（P<0.05）.Before treatment，the mRNA expressions of TLR4 and NF-κB not significant between the two groups（P>0.05）.After treatment，the mRNA expressions of TLR4 and NF-κB in the two groups were lower than those before treatment，and the expressions in the observation group were significantly lower than those in the control group（P<0.05）.There were no adverse reactions in both groups during the treatment.

By regulating TLR4/NF-κB signaling pathway，Modified Qingre Shenshi Decoction can improve the clinical symptoms of patients with ulcerative colitis，plays an anti-inflammatory role and promotes the recovery of patients，which is worthy of clinical application.