NLRP3 inflammasome plays a key role in IgA Nephropathy (IgAN) pathogenesis. Thiolutin (THL) is an NLRP3 inflammasome inhibitor with anti-inflammatory effects, but its role in IgAN is unclear. This study aimed to evaluate the protective efficacy of THL in IgAN mice, alongside assessing its inhibitory mechanisms. IgAN was induced by administration of bovine serum albumin combined with Staphylococcal Enterotoxin B in mice, followed by THL treatment. Kidney injury biomarkers, inflammatory cytokines, histological changes and the NLRP3 inflammasome pathway were assessed. The effect of THL on pyroptosis and action site on inflammasome was examined in J774A.1 cells, and co-immunoprecipitation was used to study specific protein interactions. In IgAN mice, THL treatment significantly reduced renal dysfunctional markers and histological injury without affecting hepatic function, accompanied by decreased serum IgA levels, renal IgA deposition and pro-inflammatory cytokine accumulation via regulating the mRNA and protein expression of key inflammasome components. It also attenuated pyroptosis and NLRP3 inflammasome activation instead of priming in macrophages, via disturbing the combination of NLRP3 with apoptosis-associated speck-like protein and NIMA-Related Kinase 7. THL has significant anti-inflammatory and renal protective effects in IgAN via inhibiting the NLRP3 inflammasome pathway. Its selective impact on the activation and assembly of the inflammasome, without affecting priming, highlights its potential as a targeted therapeutic agent in IgAN management.