High-speed　spindles　are　typically　installed　with　angular　contact　ball　bearings.　This　research　has　established　a　dynamic　model　for　angular　contact　ball　bearings　under　constant　preload.　By　analyzing　the　constant　preload　mechanism,　and　the　gyroscopic　and　centripetal　forces,　a　dynamic　non-linear　model　for　angular　contact　ball　bearings　was　proposed　using　Hertz　contact　theory.　The　model　was　solved　by　numerical　iteration　to　obtain　the　dynamic　parameters　of　an　angular　contact　ball　bearing　which　included:　the　dynamic　normal　contact　force　and　contact　angle,　the　maximum　compressive　stress　and　axial　displacement,　the　contact　pattern,　stiffnesses,　etc.　To　validate　the　model,　a　test　device　was　designed　which　was　equipped　with　a　constant　preloaded　bearing　group.　By　measuring　the　relative　displacement　of　the　bearings＇　inner　and　outer　rings　under　different　conditions,　the　accuracy　of　the　model　was　proved.　This　modeling　method　provided　a　theoretical　basis　for　calculating　bearing　thermal　characteristics,　fatigue　life,　and　an　optimized　radius　of　curvature　of　the　bearing　ring　channel.