The article introduces a novel concept of sequential catalytic nanomedicine for efficient tumor therapy by delivering biocompatible nanocatalysts to tumor sites. The authors integrate natural glucose oxidase (GOD) and ultrasmall Fe3O4 nanoparticles (Fe3O4 NPs) into large-pore-sized, biodegradable dendritic silica nanoparticles to create a sequential nanocatalyst. GOD depletes glucose in tumor cells, producing H2O2, which is then catalyzed by Fe3O4 NPs to generate highly toxic hydroxyl radicals through a Fenton-like reaction. This process effectively induces apoptosis and death of tumor cells. The study demonstrates the proof of concept of catalytic nanomedicine, achieving high selectivity and efficiency in tumor therapy while minimizing harm to normal tissues. In vitro and in vivo experiments show that the sequential nanocatalyst exhibits significant tumor suppression effects, with high biodegradability and biocompatibility.The article introduces a novel concept of sequential catalytic nanomedicine for efficient tumor therapy by delivering biocompatible nanocatalysts to tumor sites. The authors integrate natural glucose oxidase (GOD) and ultrasmall Fe3O4 nanoparticles (Fe3O4 NPs) into large-pore-sized, biodegradable dendritic silica nanoparticles to create a sequential nanocatalyst. GOD depletes glucose in tumor cells, producing H2O2, which is then catalyzed by Fe3O4 NPs to generate highly toxic hydroxyl radicals through a Fenton-like reaction. This process effectively induces apoptosis and death of tumor cells. The study demonstrates the proof of concept of catalytic nanomedicine, achieving high selectivity and efficiency in tumor therapy while minimizing harm to normal tissues. In vitro and in vivo experiments show that the sequential nanocatalyst exhibits significant tumor suppression effects, with high biodegradability and biocompatibility.