Prussian blue nanozymes (PBNs) with multiple enzyme activities are prepared and their activities of antitumor in nasopharyngeal carcinoma cells (CEN2) are also explored in this research. On the one hand, it shows that PBNs can exert the catalase-like (CAT-like) activity to decompose hydrogen peroxide (H₂O₂) into non-toxic H₂O in CEN2 cells. The O₂ release of H₂O₂ catalysed by PBNs effectively alleviates the hypoxic environment of tumors, which inhibits the glycolysis of tumor and reduces the production of lactic acid. On the other hand, we also find that PBNs also has peroxidase-like (POD-like) enzymatic activity, which can catalyze the production of·OH from H₂O₂ in tumor cells and result in tumor cell apoptosis. This study lays a solid biomedical foundation for the development of safe and non-toxic nanozymes, as well as the expansion of their application in tumor treatment.