Water　hydraulic　manipulators　are　suitable　for　remote　handling　maintenance　task　in　reactors.　Water　hydraulic　servo　valves　are　currently　used　in　the　manipulators,　but　water　has　the　characteristics　of　low　viscosity　and　poor　lubricity,　there　are　inevitable　leakage　and　wear　failure.　High　speed　on-off　valve　(HSV)　can　be　used　to　generate　proportional　output　and　could　be　used　to　replace　servo　valves.　In　this　research,　a　water　hydraulic　HSV　for　water　hydraulic　manipulators　is　proposed.　An　optimization　method　supported　surrogate　model,　non-dominated　sorting　genetic　algorithm　II　(NSGA-II),　and　AMESim　simulation　is　built.　And　the　effect　of　the　HSV　structure　parameters　on　dynamic　characteristic　is　analyzed　using　the　global　sensitivity　analysis.　The　Pareto　frontier　is　investigated　using　decision-making　tools　with　FUZZY,　LINMAP,　and　TOPSIS　methods,　the　best　solutions　are　selected　by　using　the　deviation　index.　The　HSV　prototype　is　fabricated,　and　the　static　and　dynamic　characteristics　experiments　of　the　HSV　are　carried　out.　The　simulation　results　showed　that,　after　optimization,　the　opening　response　time　is　reduced　by　17%,　and　the　closing　response　time　is　reduced　9%.　The　experimental　results　show　that　the　opening　response　time　and　closing　response　time　reach　5.93　ms　and　4.84　ms.