Dry　vacuum　pump　has　the　characteristics　of　no　oil　consumption,　low　pollution,　simple　structure,　wide　range　of　pumping　speed,　etc.　It　is　widely　used　in　various　semiconductor　equipment　requiring　no　oil　vapor　pollution.　The　permanent　magnet　synchronous　motor　is　the　main　power　source　of　the　dry　vacuum　pump,　and　the　torque　fluctuation　of　the　motor　rotor　in　the　electromagnetic　field　is　the　vibration　source　of　the　motor　and　the　dry　pump.　The　copper　loss,　iron　loss　and　wind　wear　generated　during　the　operation　of　the　motor　are　transmitted　to　the　drive　shaft　in　the　form　of　heat　along　the　motor　shaft,　which　will　cause　the　deformation　of　the　drive　shaft.　Usually,　the　vacuum　pump　drive　motor　adopts　water　cooling　to　dissipate　heat.　In　this　paper,　a　permanent　magnet　synchronous　motor　for　11kw　dry　vacuum　pump　is　developed　and　designed,　and　a　flow-heat　coupling　model　for　motor　cooling　is　established.　Firstly,　the　no-load　and　load　characteristics　of　the　motor　are　studied　by　using　the　JMAG　simulation　software.　Taking　the　stator　tooth　width　as　the　optimization　parameter,　the　quadratic　response　surface　method　is　used　to　optimize　the　back　EMF　harmonics　and　cogging　torque　of　the　motor,　and　the　basic　parameters　of　the　motor　are　determined.　size.　Finally,　based　on　the　calculation　of　the　electromagnetic　field　loss　of　the　motor,　the　flow　field　and　temperature　field　of　the　motor　and　the　casing　were　simulated　in　fluent,　and　the　flow　field　vector　model　of　the　cooling　liquid　in　the　coil　was　established.　Eddy　current　and　velocity　distribution　and　temperature　rise　of　water　flow.　©　2022　IEEE.