The column milling cutter can be used to machining sprocket wheel by adding a rotary axis to a rectangular coordinate system. The linear axis which connects all curves together is used to machining the teeth of sprocket wheel and the rotary axis is used to carry out the dividing movement. The subprogram is used to repeat the above movement. This method can achieve more desirable effects than the traditional method of two-dimensional machining because the consistency of the size precision of the teeth will be ensured by using the subprogram and the errors of the dividing movement will be reduced on a basis of the superposition of the design standard and the orientation standard and the setting standard. The NC technology will be improved and widened by using a common disk-shaped workbench in a NC milling machine and using the pause instruction to carry out the dividing movement manually.