In　this　work,　we　systematically　study　the　electronic　band　structures　of　fluorine-passivated　graphdiyne　nanoribbons　(F_GDYNRs)　doped　with　BN　pairs　using　first-principles　density　functional　theory　calculations.　The　calculation　results　show　that　that　fluorine　passivation　and　heteroatom　doping　play　different　roles　in　modifying　the　electronic　structures　of　F_GDYNRs.　The　former　helps　lower　the　position　of　the　valence　band　of　the　graphdiyne　nanoribbons　(GDYNRs)　while　the　latter　significantly　opens　the　band　gap　of　GDYNRs.　The　doped　F_GDYNRs　have　direct　band　gaps　of　1.8-2.9　eV,　and　their　valence　and　conduction　bands　perfectly　straddle　both　the　oxidation　and　reduction　potential　of　water.　This　work　demonstrates　that　F_GDYNRs,　via　doping　with　BN　pairs,　possess　high　catalytic　activity　for　water　splitting,　which　will　shed　light　on　the　design　of　metal-free　low-dimensional　photocatalysts.