The main heat sources of the spindle and the influence of calorific value on the precision of the spindle part group were analyzed. Large flow stable temperature oil was adopted to cool and lubricate the spindle box and the spindle bearing installation processing was optimized, in order to ensure that in highspeed operation process,the axial deformation reached less. Through experimental verification, the elongation was 0035 mm when the spindle thermal equilibrium was reached.The function between the temperature rise and thermal elongation was researched, and the axial thermal deformation was compensated, to ensure least influence on machining accuracy of workpiece in reaching thermal equilibrium process of the machine tool. 