Aiming at the problem that highspeed machine tool ball screw friction heat caused thermal elongation in axial direction, the hollow cooling method was adopted for the ball screw and nuts to restrain the temperature rising of screw. Through steady state simulation compare between the solid ball screw and the hollow ball screw under different feeding speed, the cooling method was confirmed to be effective, and hollow ball screw reaching thermal equilibrium time is far less than that of the solid ball screw through the transient simulation.