Rheumatoid arthritis has serious consequences for human health. Drugs can relieve the symptoms of some patients, but they exert significant toxic side effects. We loaded berberine into the Prussian blue nanostructure, synthesizing BRB-PB composites. It improves photothermal properties and exhibits potent anti-inflammatory and antioxidant effects. BRB-PB composites inhibited RIPK1/RIPK3/MLKL signaling pathway activation in RA synovial tissue, suggesting a unique molecular mechanism that reduces the occurrence of necroptosis and improves RA symptoms. Rapid metabolism and excellent biocompatibility of BRB-PB composites enhanced their safety and efficacy.