Abstract: Polydatin (PD) is a natural active crystalline compound extracted from the roots and stems of Polygonum cuspidatum, and is a natural precursor of resveratrol. This study aims to investigate the therapeutic effects of PD on monosodium urate (MSU)-induced gouty arthritis in mice and its potential mechanisms. The animal experiment has been approved by the Ethics Committee of Nanjing University (approval number: 2407002). A gouty arthritis model was established by injecting 20 μL of MSU (25 mg·mL^-1) suspension into the mouse plantar. The effect of PD on pathological changes in the mouse plantar was evaluated. The treatment group received daily intraperitoneal injections of different doses of PD (low dose: 5 mg·kg^-1, medium dose: 10 mg·kg^-1, high dose: 20 mg·kg^-1) for 3 days before model induction. The thickness of the mouse plantar was measured and photographed at 3, 6, 9, 12, and 24 h after MSU suspension injection. Histopathological damage to the plantar tissue was observed using hematoxylin-eosin (H&E) staining. Immunohistochemistry and immunofluorescence were used to detect the expression of NLRP3 and CASP1 p20 to assess NLRP3 inflammasome activation in the plantar tissue. At the cellular level, lipopolysaccharide (LPS) combined with adenosine triphosphate (ATP)/MSU/nigericin was used to construct a cellular activation model of the NLRP3 inflammasome. ELISA was used to detect the effect of PD on interleukin-1β (IL-1β) secretion after NLRP3 inflammasome activation in macrophages. Flow cytometry was employed to measure CASP1 p20 activation in macrophages. Immunofluorescence was used to examine NLRP3 inflammasome assembly in macrophages. The results of the study indicate that, compared to the model group, the PD-treated group exhibited a significant reduction in the swelling of the mouse plantar. H&E staining showed a notable reduction in tissue damage in the mouse plantar, suggesting that PD has a therapeutic effect on plantar damage in mice. Immunohistochemistry and immunofluorescence results revealed a significant decrease in the expression of CASP1 p20 and NLRP3, indicating that PD significantly inhibits the activation of the NLRP3 inflammasome, thereby attenuating the local inflammatory response in the mouse plantar. At the cellular level, PD treatment significantly reduced the secretion of IL-1β and activation of CASP1 p20, both of which are mediated by NLRP3 inflammasome activation. Furthermore, NLRP3 inflammasome assembly was inhibited. In summary, PD exerts its anti-inflammatory effect by suppressing the assembly and activation of the NLRP3 inflammasome, reducing the production and release of the pro-inflammatory cytokine IL-1β, thereby alleviating joint damage in mouse gouty arthritis. This provides a novel strategy for the treatment of gout.