GaN　quasi-vertical　power　devices　are　of　high　research　value　because　of　their　ability　to　introduce　current　and　electric　field　into　the　device　body,　as　well　as　their　ability　to　realize　large-area　process　production　at　low　cost.　In　this　paper,　a　GaN-based　Junction　Barrier　Schottky　diode　(JBS)　is　designed.　Firstly,　the　relationship　between　the　doping　concentration　of　P+-GaN　layer,　the　doping　concentration　of　N--GaN　layer,　reverse　voltage　and　depletion　layer　width　of　the　JBS　device　is　theoretically　calculated,　and　then　the　etching　of　the　secondary　epitaxial　window　as　well　as　the　surface　restoration　process　are　investigated.　The　P+-GaN　layer　was　etched　using　photoresist　mask　and　SiO2　mask,　and　the　etched　step　was　treated　with　TMAH　solution　and　KOH　solution.　The　SEM　(Scanning　Electron　Microscope)　test　results　show　that　the　GaN　stage　etching　with　SiO2　as　a　mask　and　the　treatment　of　the　stage　with　TMAH　solution　is　flatter　and　smoother,　which　is　more　favorable　for　the　subsequent　secondary　epitaxy　process.　Combining　the　above　results,　the　epitaxial　parameters　of　the　JBS　device　are　designed　as　follows:　the　concentration　of　the　P+-GaN　layer　is　1×1017　cm-3,　and　the　doping　concentration　of　the　N--GaN　layer　is　2×1016　cm-3;　among　the　processes,　SiO2　is　used　as　a　mask　for　the　GaN　step　etching,　and　TMAH　solution　is　used　to　repair　the　etched　surface.　©　2023　IEEE.