Study　on　internal　flow　mechanism　of　supersonic　nozzle　and　its　aerodynamic　design　methods　for　modern　liquid　rocket　engine　turbines　is　conducted　in　this　paper.　Non-Uniform　B-Spline　is　used　in　the　design　to　construct　the　nozzle　profile　due　to　its　good　adaptability　of　shape　and　ability　of　local　modification.　Two　kinds　of　nozzle　throat　design　schemes　for　supersonic　nozzle　are　discussed,　including　sharp-edged　throat　nozzle　and　slick　transition　throat　nozzle.　A　supersonic　nozzle　for　liquid　rocket　turbo-pump　hydrogen　turbines　is　analyzed　and　redesigned　as　a　design　case.　The　numerical　simulation　using　commercial　CFD　software　is　then　applied　to　predict　the　internal　flow　characteristics　and　overall　performance　of　the　nozzles.　The　results　indicate　that　the　aerodynamic　performance　of　the　redesigned　supersonic　nozzle　is　improved　clearly.　And　it　is　found　that　the　slick　transition　throat　is　much　better　than　the　sharp-angled　throat　as　it　is　not　easy　to　cause　separation　when　airflows　accelerate　and　turn　at　the　throat.