Spindle　vibration　is　a　key　factor　influencing　the　quality　of　the　processed　surfaces　during　ultra-precision　fly　cutting.　An　extremely　tiny　vibration　will　directly　influence　the　quality　of　the　surface　at　the　nanoscale.　Therefore,　in　this　study,　a　mathematical　model　of　aerostatic　spindle　vibration　under　pulsed　excitation　was　established　by　analysing　the　characteristic　cutting　path　of　a　fly　cutter　head　and　the　state　of　the　spindle　under　interrupted　cutting　force　and　then,　the　axial　and　radial　of　the　aerostatic　spindle　to　pulses　during　periodically　interrupted　fly　cutting　were　calculated　using　a　Fourier　series.　Under　the　periodic　processing　mode　of　high-speed　fly　cutting,　a　simulation　and　experimental　analysis　on　the　spindle　vibration　were　conducted.　The　experimental　results　show　that　the　cutting　force　and　spindle　speed　are　major　factors　influencing　surface　roughness.　According　to　the　simulation　and　experimental　analysis,　reliable　theoretical　guidance　is　provided　for　the　improvement　and　prediction　of　surface　quality　of　an　ultra-precision　fly　cutting.　©　2020　Inderscience　Enterprises　Ltd.