In　order　to　meet　the　requirements　of　hydraulic　servo　control　technology,　the　structural　parameters　of　the　hydraulic　flapper-nozzle　of　the　water　hydraulic　servovalves　are　studied.　By　theoretical　analysis,　the　simulation　conditions　of　the　hydraulic　flapper-nozzle　valve　are　confirmed.　Simulation　method　is　used　to　analyze　the　diameter　of　nozzle　straight　tube　and　the　diameter　and　length　of　nozzle　hole.　By　comparing　the　simulation　results,　the　diameter　of　the　straight　tube　is　set　as　1.5mm,　the　diameter　of　the　damping　hole　is　0.6mm,　and　the　length　of　the　damping　hole　is　3mm.　This　paper　would　fund　the　base　for　the　design　and　analysis　on　the　hydraulic　flapper-nozzle　valve.　©　2016　IEEE.