In　order　to　improve　the　reverse　breakdown　characteristics　of　quasi-vertical　GaN-based　Schottky　barrier　diode　(SBD),　a　junction　barrier　Schottky　diode　(JBS)　is　designed　in　this　paper,　and　device　modeling　and　characteristic　simulation　are　carried　out.　Comparing　the　SBD　and　JBS　devices　with　the　same　epitaxial　structure,　the　breakdown　voltages　of　the　devices　are　310V　and　1145V,　respectively.　Compared　to　SBD　devices,　JBS　has　a　higher　breakdown　voltage.　In　order　to　continue　to　improve　the　performance　of　the　device,　after　optimizing　the　thickness　of　the　N-GaN　drift　layer　of　the　JBS　device,　it　is　found　that　increasing　the　thickness　of　the　N-GaN　drift　layer　can　effectively　improve　the　breakdown　voltage　of　the　JBS,　but　the　on-resistance　of　the　device　also　increases　slightly.　The　breakdown　voltage　of　the　optimized　JBS　device　is　1812V;　the　ratio　of　the　area　of　the　Schottky　contact　area　to　the　area　of　the　PiN　area　will　also　affect　the　performance　of　the　vertical　JBS　device,　and　the　area　ratio　of　the　Schottky　contact　area　is　increased　from　0.379　to　0.67,　the　onresistance　of　the　device　is　reduced　from　1.097m　Omega　center　dot　cm(2)　to　0.747　m　Omega　center　dot　cm(2),　and　the　reverse　breakdown　voltage　is　slightly　reduced.　The　research　results　provide　a　theoretical　reference　for　device　structure　design　and　process　fabrication.