In order to solve the force deformation of the hydrostatic center frame in the heavy type horizontal lathe, a simulation research concerning pressure field of hydrostatic center frame was described. The Finite Volume Method of CFX has been used to compute three-dimensional pressure field of gap fluid between the rotation workpiece and bearing pillow. This research theoretically analyzes the influence of angular velocity on the bearing pressure performance according to lubricating theory and computational fluid dynamics, and it has revealed its pressure distribution law of gap oil film. The simulation results indicate that an improved characteristic will be affected by rotating velocity easily, and oil cavity pressure creases by gradually with rotating velocity enhancing. Through this method, it can provide reasonable data for design, lubrication, experience and force deformation computation for hydrostatic center frame in the heavy type horizontal lathe.