Highly　active　and　efficient　photocatalysts　are　crucial　for　the　exploration　of　ammonia　synthesis　because　of　the　serious　problem　of　energy　deficiency.　La2TiO5　(LTO)　perovskite　materials　have　great　advantages　in　the　field　of　photocatalytic　nitrogen　fixation　because　of　the　broadly　diversified　properties.　The　rational　design　of　surface　defect　is　a　valid　method　to　modulate　photoinduced　charge　traps　and　create　defect　energy　levels,　especially　it　is　an　effective　way　to　suppress　the　photoinduced　charge　recombination.　Herein,　LTO　was　obtained　by　a　simple　sol-gel　method　and　was　further　reduced　by　NaBH4　to　introduce　oxygen　defect　on　its　surface.　UV-vis　spectra　proved　that　the　surface　defects　could　reduce　the　band　gap　value　of　samples,　which　is　beneficial　for　improving　photocatalytic　nitrogen　fixation　activity.　For　the　best　photocatalytic　samples　with　good　cycle　stability,　the　nitrogen　fixation　rate　is　158.13　mu　mol.g(-1).h(-1).　The　mechanism　of　photocatalytic　nitrogen　fixation　was　proposed　by　the　PL,　XPS,　and　PEC　results,　which　provided　possibilities　for　exploring　more　promising　perovskite　catalysts　in　the　field　of　nitrogen　fixation.　(C)　2021　Elsevier　Inc.　All　rights　reserved.