N-2　reduction　reaction　(NRR)　by　light　is　an　energy-saving　and　sustainable　ammonia　(NH3)　synthesis　technology.　However,　it　faces　significant　challenges,　including　high　energy　barriers　of　N-2　activation　and　unclear　catalytic　active　sites.　Herein,　we　propose　a　strategy　of　photo-driven　ammonia　synthesis　via　a　proton-mediated　photoelectrochemical　device.　We　used　redox-catalysis　covalent　organic　framework　(COF),　with　a　redox　site　(-C=O)　for　H+　reversible　storage　and　a　catalytic　site　(porphyrin　Au)　for　NRR.　In　the　proton-mediated　photoelectrochemical　device,　the　COF　can　successfully　store　e(-)　and　H+　generated　by　hydrogen　oxidation　reaction,　forming　COF-H.　Then,　these　stored　e(-)　and　H+　can　be　used　for　photo-driven　NRR　(108.97　umol　g(-1))　under　low　proton　concentration　promoted　by　the　H-bond　network　formed　between　-OH　in　COF-H　and　N-2　on　Au,　which　enabled　N-2　hydrogenation　and　NH3　production,　establishing　basis　for　advancing　artificial　photosynthesis　and　enhancing　ammonia　synthesis　technology.