Abstract: To improve the performance of heavy load and oil-film stiffness of an NC machine's hydrostatic turntable,a new structural hydrostatic oil pad with multi-ring flow channel oil recess and damping oil seal edge is put forward and proved.Combining with the optimization design of the hydrostatic oil pads and CFD technology,the flow model of two-dimensional axial-symmetry is used for numerical simulation.The inner flow,carrying capability,and stiffness of the new structure hydrostatic oil pad are analyzed and calculated.Moreover,these data are compared with those of the traditional oil pad that has a single-chamber and single-plane.Result shows that the hydrostatic oil pad of the new structure can make turbulence appear in the damp flow-passes and the damp grooves,enhance damping,make it available of higher pressure gain and get partial hydrostatic effectiveness in grooves.Therefore,it comes true to bear heavier load and generate stronger oil-film stiffness compared with the traditional oil pad.It is available for the optimization design and performance calculation of the complex structure hydrostatic oil-pad by CFD,which increases the efficiency of design and accuracy of calculation.The study of the new hydrostatic oil pad is important to improve the performance of the heavy load hydrostatic turntable.