In this study, a simple and mild route was designed for the synthesis of novel octahedral Ni-introduced CuAu nanocages via a co-reduction process. Based on sequential reactions, Cu₂O/Au nano-octahedra were firstly prepared through galvanic displacement reaction by employing octahedral Cu₂O as the template, and then nickel and copper were introduced almost simultaneously to form the Ni-introduced CuAu nanocages by using N₂H₄·H₂O as the reducing agent and excess Cu₂O as the copper source. The peroxidase-like activity of the Ni-introduced CuAu nanocages was tested and the relevant parameters of their enzymatic activity were also investigated systematically. Compared with monometallic Cu₂O/Au nano-octahedra, Ni-introduced CuAu nanocages have superior catalytic activity, and such a magnetic catalyst could still keep a relatively high catalytic efficiency after several cycles. The results showed that the as-prepared magnetic multi-metallic nanocages could be used as an efficient recyclable peroxidase-like catalyst.