Photocatalytic　hydrogen　production,　as　an　ideal　strategy　for　solar-to-fuel　conversion,　remains　the　great　challenges　in　designing　the　highly　efficient　photocatalytic　systems.　Herein,　the　monolayer　HTi2NbO7　nanosheets　with　the　thickness　of　1.65　nm　are　developed　as　photocatalysts　coupled　with　N　nanoparticles　for　hydrogen　production　from　water.　The　N　nanocluster/HTi2NbO7　nanosheets　prepared　via　an　in　situ　process　showed　the　better　photocatalytic　activity　for　H-2　evolution　than　that　obtained　by　a　chemical　reduction.　The　higher　dispersity　and　more　closely　interface　contact　between　the　nanosheets　and　N　nanoclusters　would　promote　the　transfer　of　the　photogenerated　carriers.　A　synergistic　photocatalytic　mechanism　for　monolayer　nanosheets　and　N　nanocluster　would　be　proposed　to　elucidate　the　high　efficient　hydrogen　production.