Nanozymes constitute a category of nanomaterials presenting the potential to replace natural enzymes. Nonetheless, weak catalytic activity becomes the biggest barrier hindering their practical applications. In this study, we fabricated a montmorillonite (MMT)‐supported ruthenium (Ru)‐doped CuBi2O4 nanozyme (Ru/CuBi2O4‐MMT) with robust peroxidase (POD)‐like activity by hydrothermal method and studied its application in determination of hydroquinone (HQ). Specifically, the CuBi2O4 material is brought into nanozyme field for the first time. MMT‐supported CuBi2O4 material possesses smaller size and larger surface area than pure CuBi2O4. Ru‐doped exhibits significantly higher POD‐like activity in comparison to CuBi2O4 due to the increase of defect sites. Both of strategies synergistically enhance the POD‐like activity of CuBi2O4 material. The POD‐like activity of nanozyme originates from the photogenerated holes (h+) and superoxide radicals (•O2−) produced during the catalytic decomposition of H2O2. Ru/CuBi2O4‐MMT nanozyme can be successfully applied for HQ colorimetric detection by redox reaction. Our newly developed nanozyme exhibits exceptional POD‐like activity by introducing support and element doping strategies, holding great potential for detecting pollutants in practical applications.