Compared with oil bearings, aerostatic bearings with gas for their lubricant, have quite a few unparalleled advantages, such as lower friction losses, heats, and environmental friendliness. Especially at high speed situations, the above advantages are even crucial because of the stringent requirements for precision and ultra-precision machineries are much. Due to the compressibility of gas, it is in general a great challenge to realize a bearing of high stiffness. To overcome this difficulty (at least in certain degree), an optimized parametric design of the bearing becomes very important. Consequently, it is necessary to have a high efficiency and accuracy calculation for the time-consuming optimization.