In　order　to　solve　the　problem　that　poor　dynamic　performance　of　current　gear　measuring　instruments　seriously　affects　the　stability,　reliability　and　accuracy　of　measurement　results,　the　researches　on　the　dynamic　design　methods　of　gear　measuring　instruments　were　conducted　and　a　dynamic　design　method　combining　finite　element　analysis　and　experiment　modal　analysis　is　put　forward.　First　of　all,　the　theoretical　basis　of　dynamic　analysis,　the　basic　steps　of　finite　element　analysis　and　the　basic　principle　of　the　experiment　modal　analysis　are　studied.　Then,　taking　a　certain　gear　fast　measuring　instrument　as　example,　the　finite　element　analysis　and　experiment　modal　analysis　were　carried　out　for　the　gear　fast　measuring　instrument.　Third,　the　measuring　experiment　was　carried　out　on　the　gear　fast　measuring　instrument,　in　which　the　gears　with　different　precision　were　adopted,　and　the　tests　were　carried　out　at　different　speeds.　Finally,　the　vibration　disturbance　in　the　measurement　experiments　and　the　change　of　the　vibration　during　the　measurement　process　were　analyzed.　The　experiment　results　show　that　the　finite　element　analysis　method　can　effectively　improve　the　dynamic　performance　of　the　instrument　in　the　design　stage　and　can　improve　the　dynamic　performance　index　of　the　instrument　fundamentally.　The　experiment　modal　analysis　method　can　accurately　obtain　the　actual　dynamic　performance　index　of　the　instrument　after　the　instrument　is　manufactured,　can　effectively　carry　out　the　best　working　speed　selection　and　further　enhance　the　usage　performance　of　the　instrument.　With　the　experiments,　the　correctness　of　finite　element　analysis　and　experimental　modal　analysis　is　verified,　which　provides　a　method　for　improving　the　dynamic　precision　of　the　gear　measuring　instrument　and　provide　a　viable　way　for　reasonably　using　the　measuring　instrument.　©　2017,　Science　Press.　All　right　reserved.