Lattice　oxygen　(LO)-mediated　photothermal　dry　reforming　of　methane　(DRM)　presents　a　promising　approach　to　syngas　production.　However,　realizing　high　DRM　efficiency　and　durability　remains　challenging　due　to　the　difficulty　in　activating　LOs　in　catalysts.　Herein,　we　demonstrate　that　partially　substituting　Fe　sites　in　perovskite　ferrite　(LaFeO3)　by　Mn　triggers　LOs,　bestowing　the　catalyst　with　superior　activity　and　stability　for　photothermal　DRM　after　modification　with　Ru.　The　Mn　exchange　induces　a　charge　transfer　from　La　to　Mn,　which　combined　with　the　incoming　photoexcited　electrons　reconstructs　the　perovskite＇s　electronic　structure,　weakening　the　La-O-Mn　bonds　and　facilitating　the　LO　migration.　Meanwhile,　photogenerated　holes　migrate　to　surface　LOs,　further　enhancing　their　reactivity　to　mediate　DRM.　Under　light　irradiation,　the　catalyst　exhibits　an　outstanding　syngas　production　rate　(H2:　42.89　mol　gRu　-1　h-1,　CO:　54.92　mol　gRu　-1　h-1)　while　stably　operating　over　150　h.　It　also　achieves　a　methane　turnover　frequency　of　0.9　s-1　and　a　light-to-chemical　energy　efficiency　of　15.3%,　setting　a　benchmark　for　light-driven　DRM　performance.　This　work　underscores　the　significance　of　exact　site　doping　in　metal　oxides　to　fine-tune　LO　activity,　providing　valuable　guidance　for　fabricating　efficient　catalysts　for　solar-powered　redox　reactions　proceeded　via　the　light-supported　Mars-van　Krevelen　mechanism.