Photo-thermal　catalysis　emerged　as　a　new　fast-growing　research　area　for　volatile　organic　compounds　(VOCs)　elimination.　However,　despite　some　significant　achievements,　the　research　on　engineering　the　light　propagation　to　promote　the　photo-thermal　catalytic　efficiency　has　been　largely　overlooked　so　far.　Herein,　we　reported　Pt　nanoparticle　decorated　three-dimensionally　ordered　macroporous　(3DOM)　LaMn1.2O3　with　multiple　light　scattering　and　the　slow　photon　effect　for　improving　the　light-harvesting,　thus　achieving　synergetic　photo-　and　thermal　catalysis　toward　complete　toluene　mineralization.　As　a　result,　a　100%　conversion　of　toluene　(200　ppm　with　a　flow　rate　of　12.8　mL.min(-1))　is　achieved　with　high　selectivity　to　CO2　(88%)　and　good　stability　(100　h)　under　solar　light　irradiation.　Combining　characterizations　and　activity　experiments,　the　multiple　scattering　and　slow　photon　effect　over　Pt/3DOM　LaMn1.2O3　are　confirmed　to　enhance　the　reducibility　and　migration　of　lattice　oxygen　and　facilitate　the　migration　of　the　charge　carrier,　thus　contributing　to　the　improved　photo-thermal　catalytic　performance.　This　work　demonstrates　that　a　well-considered　design　of　catalysts　with　optimized　structural　and　electronic　properties　effectively　maximizes　solar　energy　utilization.