In　order　to　predict　the　machining　precision　of　the　machine　tool　and　validate　its　design　concept,　the　geometric　errors　of　a　precise　vertical　machining　center　were　analyzed,　and　its　precision　prediction　model　was　established　based　on　the　multi-body　system　theory.　The　correlations　among　the　multi-bodies　were　described　with　the　topology　structure　and　the　low-order　body　array.　The　coordinate　transformation　relationships　between　multi-bodies　were　described　based　on　the　homogeneous　transformation　matrix.　The　characteristic　matrix　and　the　relative　motion　equations　of　the　motions　between　2　arbitrary　adjacent　objects　of　the　multi-body　system　were　derived.　A　precision　prediction　model　was　built　for　the　precise　vertical　machining　center.　Based　on　the　simulated　machining　of　a　typical　workpiece,　the　precision　prediction　of　the　machine　tool　was　realized.　The　results　showed　that　the　proposed　precision　model　can　describe　the　systemic　structure　of　the　vertical　machining　center　effectively　and　abstractively,　predict　the　machining　precision　reasonably,　provide　a　basis　for　the　improvement　of　the　machine　tool　design　concept　and　the　precision　deployment.