Based　on　the　structure　characteristics　of　electric　spindle　built-in　motor　and　numerical　heat　transfer　theory,electric　spindle　built-in　motor　physical　heat　conduction　model　was　given　and　a　mathematical　temperature　control　model　for　the　electric　spindle　built-in　motor　was　established.　According　to　the　mathematical　temperature　control　model,　controllable　factors　for　the　heat　balance　was　determined.　By　electric　spindle　own　screw　channels,　using　this　mathematical　temperature　control　model　to　adjust　the　flow　speed　and　fluid　medium　temperature,　the　built-in　motor　quickly　reached　heat　balance　and　maintained　temperature　field　stability　in　the　electric　spindle　start-stop　and　using　process.　Then　the　theoretical　calculations　and　simulation　on　the　electric　spindle　built-in　motor　was　conducted.This　model　is　designed　to　enhance　high-speed　precision　spindle　machining　accuracy　and　the　use　of　performance.　©　(2013)　Trans　Tech　Publications,　Switzerland.