To analyze the effective chemical components and action targets of Dahuang Mudan Decoction,and to study the mechanism of its treatment for ulcerative colitis(UC).Methods:Chinese Medicine System Pharmacology Technology Platform(TCMSP) database was used to search for the active ingredients and target proteins of Dahuang Mudan Decoction; the genomic annotation database platform(Genecards)was used to predict the target of the disease,and then make the drug-target-disease relationship into a network Graphic form; the PPI network was constructed using the String database platform,and we searched for PPI core genes,and then performed GO enrichment analysis and KEGG enrichment analysis to find out the signal pathways involved and constructed a target-path network graph.Results:After screening,a total of 18 key chemical components of Dahuang Mudan Decoction for UC were obtained,and 28 common targets were obtained,and 15 PPI core genes were obtained,namely MYC,JUN,CASP3,ESR1,PTGS2,HSP90AA1,CASP8,CASP9 IL1B,CCNB1,CDKN1A,CHEK1,PPARG,BAX,KDR; GO enrichment analysis results included ultraviolet stress,membrane raft,cysteine-type endopeptidase activity involved in the apoptosis process,etc; KEGG enrichment pathways included P53 signaling pathway,small cell lung cancer signaling pathway,hepatitis B signaling pathway,and colorectal cancer signaling pathway.Conclusion:Dahuang Mudan Decoction can inhibit inflammation and regulate immune function by regulating the targets of PTGS2,PTGS1,HSP90AA1,BAX,CASP3,ESR1,ESR2,FASN,JUN,NOS2,etc.to suppress inflammation and regulate immune function.