In　a　water　hydraulic　jet　pipe　servo　valve,　the　overall　performance　of　the　valve　is　directly　influenced　by　the　structure　dimension　of　the　receiver　and　the　prestage-　jet　pipe　amplifier.　This　paper　deals　with　the　influence　rules　of　the　structure　dimension　parameters　and　performance　parameters　on　the　buildup　pressure　in　the　two　receiving　holes,　including　the　vertical　clearance　between　the　nozzle　and　the　receiver,　the　diameter　of　the　nozzle　hole,　the　diameter　of　the　receiving　orifice,　and　the　nozzle　offset　distance.　The　best　combination　of　structure　size　is　finally　obtained　by　using　numerical　simulation,　computer　emulation　and　experiment　analysis　methods.　Then　build　up　the　finite　volume　analysis　models　about　the　pressure　field　and　the　speed　field　of　the　jet　pipe　amplifier.　Through　analyzing　the　characteristics　of　the　flow　field,　a　mathematics　relation　between　the　jet　nozzle　offset　and　the　pressure　ratio　inside　the　two　receiver　holes　is　established,　which　reveals　the　energy　distribution　and　conversion　mechanism.　The　conclusion　could　be　an　important　reference　for　the　design　and　research　of　jet　pipe　servo　valve.　©　(2012)　Trans　Tech　Publications,　Switzerland.