Chemodynamic therapy (CDT) is a promising and potent therapeutic strategy for the treatment of cancer. We developed a DNA origami-based enzymatic cascade nanoreactor (DOECN) containing spatially well-organized Au nanoparticles and ferric oxide (FeO) nanoclusters for targeted delivery and inhibition of tumor cell growth. The DOECN can synergistically promote the generation of hydrogen peroxide (HO), consumption of glutathione, and creation of an acidic environment, thereby amplifying the Fenton-type reaction and producing abundant reactive oxygen species, such as hydroxyl radicals (•OH), for augmenting the CDT outcome. The DOECN is decorated with targeting groups to achieve efficient cellular uptake and efficiently induce tumor cell apoptosis, ferroptosis, and immunogenetic cell death, thus realizing potent anticancer therapeutic effects. Intravenous injection of the DOECN effectively promoted the maturation of dendritic cells, triggered adaptive T cell responses, and suppressed tumor growth in a murine cancer model. The DOECN provides a programmable platform for the integration of multiple therapeutic components, showing great potential for combined cancer therapy.