Vibration　characteristics　of　heavy　CNC　machine　tools　are　directly　affected　by　their　foundations.　To　analyze　vibrations　of　heavy　CNC　machine　tools　caused　by　internal　and　external　loads,　a　system　dynamics　model　of　a　rigid-flexible　coupled　heavy-duty　CNC　machine　tool-foundation　system　was　established　based　on　the　multibody　transfer　matrix　method.　Since　joint　surfaces　can　seriously　affect　the　accuracy　of　system　mechanics　models,　the　substructure　synthesis　method　was　first　used　to　establish　a　dynamic　model　of　the　joint　surface.　The　frequency　response　function　was　then　used　to　identify　model　parameters.　Moreover,　to　improve　the　accuracy　of　parameter　identification　of　the　joint　surface,　a　residual　frequency　compensation　function　was　used　to　reconstruct　the　frequency　response　function.　Finally,　the　multibody　system　model　was　implemented　by　combining　surface　elements.　To　verify　the　system　dynamics　model,　an　experimental　model　of　the　heavy-duty　machine-foundation　system　was　built,　taking　into　consideration　joint　surface　factors,　and　the　theoretical　model　was　validated　by　comparing　theoretical,　simulation,　and　experimental　results.　Using　the　theoretical　model,　the　influence　of　different　forms　of　concrete　foundations,　materials,　and　soil　properties　on　the　vibration　characteristics　of　heavy-duty　CNC　machine　tools　was　analyzed,　thus　providing　a　theoretical　basis　for　optimizing　and　improving　CNC　machine　tools.