the　safety　and　reliability　of　household　power　distribution　switch　is　very　important,　how　to　design　a　power　distribution　switch　with　strong　breaking　ability　and　reliable　work　is　the　goal　of　most　designers.　In　this　paper,　a　miniature　circuit　breaker　of　rated　current　63A　is　used　as　the　research　object.　From　the　perspective　of　virtual　simulation,　through　the　thought　of　3D　analysis　of　the　calculation　model　of　the　overcurrent　tripping　mechanism,　the　combination　of　dynamics　software　and　finite　element　analysis　software　to　design　a　prototype　of　the　virtual　design　and　analysis　platform.　The　design　prototype　uses　interactive　data　transmission　technology　for　structural　design,　platform　can　automatically　add　constraint,　realize　the　electromagnetic　field　calculation,　through　the　design　platform,　and　the　related　parameters　were　analyzed　in　order　to　further　improve　for　the　performance　of　the　prototype　theory　basis.