Improving　the　machining　accuracy　of　the　heavy-duty　CNC　machine　tools　is　a　hot　topic　in　the　high-end　equipment　field,　but　there　is　little　research　on　the　impact　of　foundation　settlement　deformation　on　machine　tool　accuracy.　In　order　to　study　the　law　of　changes　in　the　machining　accuracy　of　heavy-duty　CNC　machine　tools　caused　by　the　foundation　deformation,　based　on　the　Euler　Bernoulli　beam　element　theory,　the　interaction　between　the　foundation　and　the　machine　tool　are　considered,　the　integrated　deformation　coordination　equation　of　the　machine　tool　structure　and　the　basic　system　can　be　established,　taken　the　position　and　attitude　change　of　the　midpoint　of　the　beam　as　the　goal,　the　node　coordinate　calibration　scheme　in　the　process　of　solving　the　overall　stiffness　matrix　are　analyzed;　according　to　similarity　theory,　the　scale　model　of　the　heavy-duty　CNC　machine　tool-basic　system　are　created,　the　static　displacement　deformation　relationship　between　the　designed　scale　model　and　the　original　scale　model　of　the　machine　tool　are　analyzed,　and　the　mapping　law　of　the　scale　model　and　the　original　scale　model　can　be　obtained,　provide　basis　and　technical　support　to　effectively　solve　the　foundation　settlement　caused　The　machine　tool　accuracy　change　and　accuracy　compensation.　©　2022　Journal　of　Mechanical　Engineering.