Chemodynamic therapy (CDT) is an emerging therapy method that kills cancer cells by converting intracellular hydrogen peroxide (H O ) into highly toxic hydroxyl radicals ( OH). To overcome the current limitations of the insufficient endogenous H O and the high concentration of glutathione (GSH) in tumor cells, an intelligent nanocatalytic theranostics (denoted as PGC-DOX) that possesses both H O self-supply and GSH-elimination properties for efficient cancer therapy is presented. This nanoplatform is constructed by a facile one-step biomineralization method using poly(ethylene glycol)-modified glucose oxidase (GOx) as a template to form biodegradable copper-doped calcium phosphate nanoparticles, followed by the loading of doxorubicin (DOX). As an enzyme catalyst, GOx can effectively catalyze intracellular glucose to generate H O , which not only starves the tumor cells, but also supplies H O for subsequent Fenton-like reaction. Meanwhile, the redox reaction between the released Cu ions and intracellular GSH will induce GSH depletion and reduce Cu to Fenton agent Cu ions, and then trigger the H O to generate OH by a Cu -mediated Fenton-like reaction, resulting in enhanced CDT efficacy. The integration of GOx-mediated starvation therapy, H O self-supply and GSH-elimination enhanced CDT, and DOX-induced chemotherapy, endow the PGC-DOX with effective tumor growth inhibition with minimal side effects in vivo.