Immune　checkpoint　blockade　(ICB)　is　emerging　as　a　promising　therapeutic　approach　for　clinical　treatment　against　various　cancers.　However,　ICB　based　monotherapies　still　suffer　from　low　immune　response　rate　due　to　the　limited　and　exhausted　tumor-infiltrating　lymphocytes　as　well　as　tumor　immunosuppressive　microenvironment.　In　this　work,　the　cell　membrane　with　surface　displaying　PD-1　proteins　(PD1-CM)　was　prepared　for　immune　checkpoint　blockade,　which　was　further　combined　with　multifunctional　and　biodegradable　MnO2　for　systematic　and　robust　antitumor　therapy.　The　MnO2-based　gene-engineered　nanocomposites　can　catalyze　the　decomposition　of　abundant　H2O2　in　TME　to　generate　O2,　which　can　promote　the　intratumoral　infiltration　of　T　cells,　and　thus　improve　the　effect　of　immune　checkpoint　blockade　by　PD-1　proteins　on　PD1-CM.　Furthermore,　MnO2　in　the　nanocomposites　can　be　completely　degraded　into　Mn2+,　which　can　catalyze　the　generation　of　highly　toxic　hydroxyl　radicals　for　chemodynamic　therapy,　thereby　further　enhancing　the　therapeutic　effect.　In　addition,　the　prepared　nanocomposites　possess　the　advantages　of　low　cost,　easy　preparation　and　good　biocompatibility,　which　are　expected　to　become　promising　agents　for　combination　immunotherapy.　©　2022　The　Authors