Triptolide, a principal bioactive compound derived from Tripterygium wilfordii Hook f., has shown efficacy in treating membranous nephropathy (MN), yet its precise pharmacological mechanisms remain unclear. This study employed an integrated approach combining network pharmacology and experimental validation to systematically elucidate the molecular mechanisms underlying triptolide’s therapeutic effects in MN. Potential targets of triptolide and MN-associated targets were retrieved from publicly accessible databases. A protein–protein interaction (PPI) network was constructed, followed by Gene Ontology (GO) and KEGG pathway enrichment analyses, to establish target-pathway networks and identify key therapeutic targets and pathways. Molecular docking was performed to validate interactions between triptolide and hub targets. Additionally, passive Heymann nephritis (PHN) rat models were generated to experimentally confirm the molecular mechanisms of triptolide in MN treatment. Network pharmacology analysis identified 118 overlapping targets of triptolide relevant to MN, including mTOR, STAT3, CASP3, EGFR, and AKT1. Enrichment analyses highlighted involvement of signaling pathways such as PI3K/AKT, MAPK, Ras, and Rap1 in triptolide-mediated MN therapy. Molecular docking confirmed strong binding affinities of triptolide with PIK3R1, AKT1, and mTOR. In vivo studies demonstrated that triptolide significantly reduced 24-hour urinary protein levels (P < 0.01) and alleviated renal injury in PHN rats. Triptolide treatment also increased serum albumin while lowering total cholesterol, triglycerides, and low-density lipoprotein levels (P < 0.05). Western blot analyses indicated modulation of the PI3K/AKT/mTOR pathway in the triptolide-treated group compared to PHN controls. Triptolide exhibits renoprotective and antiproteinuric effects in PHN, likely through regulation of the PI3K/AKT/mTOR signaling pathway. These findings clarify the molecular mechanisms of triptolide in MN therapy and offer a scientific foundation for further basic and clinical investigations.