The　outcome　of　radiotherapy　is　significantly　restricted　by　tumor　hypoxia.　To　overcome　this　obstacle,　one　prevalent　solution　is　to　increase　intratumoral　oxygen　supply.　However,　its　effectiveness　is　often　limited　by　the　high　metabolic　demand　for　O-2　by　cancer　cells.　Herein,　we　develop　a　hybrid　semiconducting　organosilica-based　O-2　nanoeconomizer　pHPFON-NO/O-2　to　combat　tumor　hypoxia.　Our　solution　is　twofold:　first,　the　pHPFON-NO/O-2　interacts　with　the　acidic　tumor　microenvironment　to　release　NO　for　endogenous　O-2　conservation;　second,　it　releases　O-2　in　response　to　mild　photothermal　effect　to　enable　exogenous　O-2　infusion.　Additionally,　the　photothermal　effect　can　be　increased　to　eradicate　tumor　residues　with　radioresistant　properties　due　to　other　factors.　This　＂reducing　expenditure　of　O-2　and　broadening　sources＂　strategy　significantly　alleviates　tumor　hypoxia　in　multiple　ways,　greatly　enhances　the　efficacy　of　radiotherapy　both　in　vitro　and　in　vivo,　and　demonstrates　the　synergy　between　on-demand　temperature-controlled　photothermal　and　oxygen-elevated　radiotherapy　for　complete　tumor　response.　Tumor　hypoxia　is　a　major　limitation　in　radiotherapy,　and　strategies　to　address　this　often　fail　due　to　high　oxygen　consumption.　Here,　the　authors　report　a　nanomaterial　assembly　for　the　simultaneous　reduction　in　mitochondrial　respiration　and　to　supply　oxygen　to　potentiate　radiotherapy.