A plasmonic bimetallic nanostructure has attracted considerable attention as a promising catalyst for light-driven catalytic reactions. The stability and recovery of the catalysts are still key issues for sustainable development of green chemistry. In this work, we designed and implemented an Au/Pd heterojunction@mesoporous SiO₂ yolk–shell nanostructure (Au/Pd@m-SiO₂ yolk–shell NPs) for plasmon-enhanced photocatalysis. The heterojunction of Au/Pd enhances the separation of hot electrons and holes under visible light irradiation, and the mesoporous SiO₂ shell protects the active Au/Pd NPs from aggregation. The Au/Pd@m-SiO₂ yolk–shell NPs exhibit extremely high stability for the plasmon-enhanced catalytic reduction of p-nitrophenol (4-NP) under visible light irradiation. The merging of a plasmonic material and a yolk–shell nanostructure proposes a new way for designing catalysts with good stability and promising activity.