Purpose:　Trephination　is　one　of　the　basic　operations　of　keratoplasty,　and　the　biomechanical　mechanism　of　the　operation　can　be　revealed　based　on　three-dimensional　modeling　and　simulation　of　trephine　cutting　cornea.　Methods:　Based　on　the　analysis　of　the　physical　and　biomechanical　characteristics　of　corneal　trephination,　a　three-dimensional　numerical　model　of　corneal　trephination　is　built,　where　the　cornea　can　be　simplified　to　two　layers　structure　including　stroma　and　epithelium,　and　the　trephine　cuts　the　cornea　under　the　vertical　motion　load　and　the　rotational　motion　load.　A　three-dimensional　failure　criterion　of　corneal　material　is　proposed　based　on　the　yield　strength　theory.　On　this　basis,　trephination　simulation　is　carried　out,　and　the　units　of　corneal　material　are　removed　from　the　model　when　they　meet　the　defined　failure　criterion.　Results:　Under　the　given　parameters　including　the　velocity,　the　angle　and　the　angular　velocity,　the　trephine　force　curves,　include　the　linear　cutting　force　and　the　rotary　cutting　force　are　obtained,　and　show　the　change　of　the　forces　with　displacement　during　the　process　of　trephination　simulation.　The　maps　of　the　equivalent　stress　show　the　destruction　and　deformation　of　the　cornea.　Then,　the　experiment　of　robotic　trephination　is　carried　out　under　the　same　parameters　and　the　effectiveness　of　the　simulation　is　evaluated.　Conclusions:　Based　on　mechanics　theory　and　finite　element　method,　the　process　of　trephine　cutting　cornea　has　been　reproduced,　and　the　interaction　mechanism　is　revealed,　which　lays　the　foundation　for　the　development　of　real-time　simulation　and　virtual　system　of　the　corneal　surgery.