The　construction　of　a　light-assisted　thermal　catalytic　system　has　great　potential　in　the　reverse　water　gas　shift　reaction　(RWGS).　To　explore　the　role　of　light　in　the　thermo-catalytic　system,　a　prepared　Cu-CeO2　sample　was　performed　for　the　RWGS　reaction　under　visible　light　irradiation.　It　was　found　that　Cu-CeO2　sample　shows　an　excellent　RWGS　catalytic　activity　and　CO　selectivity,　and　the　production　of　CO　with　light　introduction　has　been　significantly　increased　by　30　%　at　250　degrees　C.　A　combination　of　In-situ　DRIFTS,　Quasi-situ　EPR,　and　XPS　characterization　results　demonstrate　that　under　visible　light　irradiation,　the　localized　surface　plasmon　resonance　(LSPR)　produced　by　Cu　nanoparticles　stimulates　hot　electrons　transfer　and　attack　to　the　bidentate　formats　and　linear-CO　intermediate　species,　resulting　in　that　accelerating　the　decomposition　and　desorption　of　intermediate　species　into　CO,　but　inhibiting　further　reduction　of　CO.　Moreover,　the　spillover　of　H-2　from　Cu　to　CeO2　surface　is　also　affected　by　light　due　to　the　observed　regeneration　of　oxygen　vacancies　on　the　CeO2　surface,　which　together　influence　the　yield　of　CO.　This　work　shows　that　introducing　visible　light　could　improve　RWGS　reaction　activity　and　retain　the　selectivity　of　CO,　which　maybe　provide　a　new　approach　to　control　the　product　selectivity　for　a　thermal　catalytic　reaction.