Chemodynamic therapy (CDT) offers a promising alternative to conventional cancer treatment. However, the limited acidity and H₂O₂ concentration in tumor microenvironment (TME) severely impair the anticancer effects of CDT. In this study, we report a microemulsion-assisted coassembly method to prepare iron(III) tetraphenylporphyrin (FeTPP) and magnetic (Fe₃O₄) nanocomposite material (FeTPP@Fe₃O₄), using photoactive FeTPP and Fe₃O₄ nanocrystals as building blocks. The self-assembling nature of FeTPP results in disordered aggregation and fluorescence quenching, leading to a high light-to-heat conversion efficiency. Continuously, the photo-thermal effect enhances the catalytic decomposition of hydrogen peroxide (H₂O₂) in the Fenton reaction on Fe₃O₄ nanocrystals to generate highly toxic hydroxyl radicals (·OH) to destroy cancer cells. This cascade reaction produces a synergistic therapeutic effect between CDT and photothermal therapy (PTT), which significantly amplifies the therapeutic effect and enhances the treatment outcome of cancer patients. The highly efficient tumor catalytic therapy in vivo results confirmed that this nanomedicine treatment is an excellent biocompatible catalytic nanomedicine therapy achieved through a photo-enhanced Fenton reaction activity approach.