Introduction: Thlaspi arvense (TA), commonly known as "Ximi" or "Subaijiang," is a traditional Chinese medicinal herb used to prevent and treat ulcerative colitis (UC). However, the precise mechanisms underlying its therapeutic effects remain unclear, necessitating further investigation to identify potential pharmaceutical applications for UC management. This study aims to elucidate the efficacy and mechanisms of TA and its active constituents in UC treatment. Methods: This study first evaluated the effects of varying TA doses on 3% dextran sulfate sodium (DSS)-induced UC. Gut microbiota alterations in UC mice were analyzed via 16S rRNA sequencing, with correlation analyses to reveal the relationship between gut microbiota and cytokines. Then, network pharmacology was utilized to identified potential TA targets for UC treatment. Protein-protein interaction (PPI) networks, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were employed to explore TA's mechanisms. Molecular docking and dynamics simulations validated interactions between TA's active compounds and UC-related targets. Finally, TNF pathway modulation by TA and its active component, isovitexin, was verified Results: TA alleviated DSS-induced weight loss in a dose-dependent manner, reduced disease activity indices, and preserved intestinal mucosal barrier integrity. Subsequently, fluorescence Discussion: Collectively, Thlaspi arvense (TA) ameliorates ulcerative colitis through synergistic mechanisms involving gut microbiota modulation, inflammatory pathway suppression, and intestinal barrier preservation. By remodeling microbial communities to reduce