Since　the　rotational　characteristics　of　the　aerostatic　spindle　are　formed　by　the　coupling　of　the　load　bearing　characteristics　of　the　aerostatic　bearing　and　the　operating　characteristics　of　the　rotor,　the　imbalance　factors　of　the　spindle　during　the　operation　and　manufacturing　errors　in　processing　have　an　impact　on　the　performance　of　aerostatic　bearings　inevitably.　Thus　this　paper　analyzes　the　static　and　dynamic　characteristics　of　aerostatic　bearings　under　the　influence　of　imbalance　factors　and　manufacturing　errors.　With　the　established　dynamic　model　of　the　aerostatic　journal　bearing,　the　rotational　errors　analysis　of　the　aerostatic　spindle　is　realized.　The　correctness　of　the　simulation　results　is　verified　by　comparing　the　experimental　data　with　the　simulation　data.　The　data　provides　a　theoretical　basis　to　accurately　predict　the　rotational　errors　of　the　spindle　system　and　achieve　accuracy　control.