Multifunctional　cancer　treatments　based　on　gas　therapy　combined　with　other　cancer　treatments　have　gained　tremendous　attention　and　hold　great　promise　in　biomedical　applications.　In　this　study,　a　carbon　monoxide-releasing　nanoplatform　combined　with　near-infrared　(NIR)　laser-triggered　photothermal　therapy　(PTT)　was　constructed.　The　nanoplatform　was　composed　of　manganese　pentacarbonyl　bromide　(MnCO)-loaded　g-carbon　nitride/polypyrrole　(CNPpy)　nanomaterials　(MnCO@CNPpy).　MnCO　can　be　triggered　to　produce　CO　under　H2O2　conditions.　Upon　exogenous　NIR　light　stimulation　and　tumor　microenvironment-overexpressed　H2O2,　MnCO@CNPpy　exhibited　excellent　CO　generation　performance　and　photothermal　effect.　The　generation　of　CO　induced　intracellular　oxidative　stress　and　caused　cell　apoptosis.　Additionally,　photoacoustic　(PA)　imaging　was　performed　to　track　the　delivery　and　accumulation　of　the　nanomaterial　in　tumor　sites　because　of　the　great　photothermal　conversion　of　CNPpy.　The　presented　MnCO@CNPpy　nanoplatform　displayed　desirable　PTT　and　CO　therapy　in　the　inhibition　of　tumor　growth　and　may　provide　a　promising　strategy　for　multifunctional　antitumor　synergistic　treatments.　©　2021　American　Chemical　Society.