A　water　hydraulic　direct-driven　high-speed　on-off　valve　was　introduced　for　the　water　hydraulic　robots.　And　a　physical　model　was　established　by　AMESim　simulation　software,　and　the　dynamic　performance　was　simulated.　On　this　basis,　the　effect　of　such　structure　parameters　as　the　valve　core　diameter,　valve　hole　diameter　and　half　cone　angle　of　valve　core　for　the　water　hydraulic　high-speed　on-off　valve　was　analyzed　by　using　AMESim　batch　method,　and　based　on　the　genetic　algorithm,　the　dynamic　characteristics　of　the　water　hydraulic　on-off　valve　were　analyzed　when　the　multi-parameters　chandged.　Then,　the　optimal　structural　parameters　of　the　on-off　valve　were　achieved,　and　a　theoretical　basis　for　the　the　improvement　of　dynamic　performance　was　provided.　Finally,　a　prototype　of　water　hydraulic　high-speed　on-off　valve　was　developed,　and　the　experimental　study　on　the　dynamic　performance　was　carried　out.　The　opening　response　time　was　7　ms,　closing　response　time　was　9　ms.　Through　the　comparison　of　theory　and　experiment,　it　verifies　that　the　dynamic　performance　of　the　developed　model　can　meet　the　expected　technical　requirements.　©　2017,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.