Computer　numerical　control　(CNC)　precision　vertical　grinder　has　the　advantages　of　less　deformation　and　better　roundness　during　processing.　It　is　widely　used　in　the　grinding　field　of　sleeve,　disk,　ring,　small　table　and　other　parts　in　the　machine　tool　industry.　Compared　with　foreign　countries,　domestic　machine　tool　industry　in　the　field　of　high-end　grinding　machine　has　low　production　efficiency,　poor　machining　accuracy　and　other　problems.　In　this　paper,　with　a　type　of　CNC　precision　vertical　grinding　machine　as　the　research　object,　first　of　all,　through　the　study　of　motion　relationship　between　the　key　components,　the　corresponding　geometric　error　parameters　were　obtained,　and　then　parts　were　built　based　on　multi-body　system　theory,　the　transformation　matrix　between　the　grinding　machine　precision　machining　constraint　equation　was　obtained,　and　thus　space　of　the　grinding　machine　geometric　error　model　was　established.　Based　on　the　spatial　geometric　error　model,　the　error　sensitivity　model　was　established,　and　the　key　error　terms　affecting　the　machining　accuracy　were　obtained.　Finally,　the　key　error　items　were　repaired　to　complete　the　machining　accuracy　optimization　of　CNC　vertical　grinder,　which　can　provide　a　theoretical　basis　for　the　design　of　vertical　grinding　machine.　©　2024　Beijing　University　of　Technology.　All　rights　reserved.