<p>Peroxidase is widely used in biotechnology, medicine and industrial production, but for natural enzymes, its application is limited by the short half-life, poor substrate selectivity and variability. However, nanozymes have the characteristics of simplicity, high efficiency and stability, which can make up for the deficiency of natural enzymes. In this paper, cerium nitrate hexahydrate (Ce(NO₃)₃·6H₂O) was used as raw material to synthesize Cerium oxide nanomaterials (CeO₂NPs) by hydrothermal synthesis, and then Cerium oxide/cobalt(II) phthalocyanine (CeO₂NPs@CoPc) and Cerium oxide/copper phthalocyanine (CeO₂NPs@CuPc) composites were synthesized by mixed sintering. The spectra, structure, morphology and element content were characterized. It has been verified that CeO₂NPs had peroxidase-like activity with the double substrates system. The optimal temperature and pH of the enzymatic reaction of CeO₂NPs, CeO₂NPs@CoPc and CeO₂NPs@CuPc were determined to be 35&#xa0;°C and 3.5, respectively. The order of catalytic activity of the enzymes was: CeO₂NPs@CoPc &gt; CeO₂NPs@CuPc &gt; CeO₂NPs. Except for Na⁺ and Cl⁻, the other ions could promote the catalytic activity of the three materials. Moreover, the steady-state dynamics of the three materials were analyzed. The experimental results of mechanism showed that the catalytic ability of the materials was improved by producing more ·OH and increasing the content of Ce³⁺, which indicated that phthalocyanine (Pc) was beneficial to enhance the peroxidase activity of the materials. Finally, an analytical method was obtained with good linearity and high sensitivity for quantitative detection of dopamine hydrochloride. The results of this study will provide an experimental basis and basis for the development and application of nano-mimetic enzyme materials, and also provide an idea for the development of CeO₂NPs.</p>