The　photo-assisted　thermal　catalytic　system　has　provided　a　new　alternative　way　to　drive　highly　efficient　CO2　methanation　reaction.　In　this　work,　we　investigated　the　role　of　visible　light　for　thermal　catalytic　methane　synthesis,　emphasizing　the　synergy　effect　of　Ni　doping　and　oxygen　vacancies　for　the　hydrogenation　of　CO2　over　Ni-CeO2　catalysts.　It　was　found　that　the　optimal　7.5　wt%　Ni-CeO2　catalysts　exhibited　the　best　visible　light-promoted　CO2　methanation　performance.　At　250　degrees　C,　the　light-promoted　performance　increased　from　0.67　to　0.93　mmol(-1).g(-1).h　which　increased　by　39　%.　Extensive　characterization　demonstrates　that　heteroatom　Ni　doping　increases　the　content　of　oxygen　vacancies　which　narrows　the　band　gap　and　improves　the　electron　density　of　the　catalyst,　resulting　in　accelerating　the　transformation　of　carbonate　and　CO　intermediate　species　which　is　beneficial　to　yield　CH4.　Furthermore,　the　visible-light-induced　regeneration　of　oxygen　vacancies　also　provides　more　active　site　to　facilitate　the　adsorption　and　activation　of　CO2　which　co-promoted　the　photo-assisted　thermal　catalytic　CO2　methanation　reaction.　The　synergy　effect　of　Ni　doping　and　oxygen　vacancies　provide　a　new　strategy　to　design　a　high-efficiency　photo-assisted　thermal　catalyst.