Composite　grinding　machine　for　non-circular　shaft　parts,　on　the　workpiece　servo　spindle　high　requirements.In　order　to　overcome　the　vector　control　coordinate　calculation　of　complex,　slow　response　speed　and　other　defects,　this　paper　adopts　the　direct　torque　control　scheme　of　asynchronous　motor　spindle　servo　control　research.Using　the　Matlab/Simulink　module　library　provides　the　basic　module,　built　asynchronous　electric　spindle　direct　torque　control　system　model.Coordinate　transformation　process　were　established,　flux　adjust　step,　flux　observation,　link　and　loop　PID　position　control　module,　and　the　use　of　subsystem　package　technology　package.The　current　loop,　speed　loop,　ring　in　position　and　torque　simulation　test,　the　results　show　that,　the　method　of　direct　torque　control　of　asynchronous　motor　spindle　control　drive　control　system　can　obtain　good　static　and　dynamic　response　characteristics　and　the　closed-loop　response　performance.　©　(2013)　Trans　Tech　Publications,　Switzerland.