©　2018,　Science　Press.　All　rights　reserved.　In　order　to　prepare　ZnO　nanowires　with　excellent　field　emission　performance,　the　growth　mechanism　and　field　emission　performance　were　studied.　Firstly,　the　high　aspect　ratio　ZnO　nanowires　were　prepared　by　the　optimized　two-step　method.　Secondly,　the　morphologies　of　ZnO　were　characterized　by　SEM.　Then,　based　on　the　analysis　of　the　morphological　features,　the　rapid　growth　mechanism　of　the　ZnO　nanowires　film　under　strong　alkali　conditions　were　described.　Finally,　the　field　emission　performance　of　a　typical　sample　was　tested.　The　test　results　show　that　with　the　optimized　two-step　method,　nanowires　with　a　diameter　of　40　∼　50　nm,　a　length　of　2.2　∼　2.7　μm,　and　an　aspect　ratio　of　up　to　54　can　be　obtained　in　only　3　h.　The　turn-on　field　of　the　film　is　3.6　V/um,　the　threshold　electric　field　is　9.　1　V/μm,　and　the　field　enhancement　factor　β　is　as　high　as　3　391.　Studies　have　shown　that　high　pH　solution　can　accelerate　the　preferential　growth　of　ZnO　nanowire　along　the　C-axis　direction,　obtain　high　aspect　ratio　ZnO　nanowires,　thereby　obtaining　excellent　field　emission　performance.