Fabrication of high-performance artificial antioxidant enzyme (AAE) systems based on a single nanozyme possessing multi-enzymatic activities is fascinating but challenging. Here, polyvinylpyrrolidone (PVP)-platinum-copper nanoparticle clusters (PVP-PtCuNCs) are prepared by a facile one-pot chemical coreduction method. PVP-PtCuNCs possess efficient superoxide dismutase (SOD)-like, peroxidase (POD)-like, and catalase (CAT)-like activities, and the multi-enzymatic activities depend on the bimetal component and cluster structure. Compared with individual platinum nanoparticle clusters (PVP-PtNCs), PVP-PtCuNCs can effectively eliminate reactive oxygen species (ROS) including superoxide anions, hydrogen peroxide, and hydroxyl radicals. The doping of copper not only reduces the usage of Pt content but also improves the catalytic efficiency and versatility effectively through the synergistic effect of bimetal components and the nanocluster structure. The results not only demonstrate that a single bimetallic nanozyme has the potential as an efficient AAE system in the biomedical application but also demonstrate that traditional concepts of structure-activity relationships can be used to fabricate nanozymes with the desired multi-enzymatic activities.