The air-floating guide rail belongs to the effect of gas dynamic and static pressure, achieving smooth movement without friction and vibration. It has the characteristics of high running precision, clean, pollution-free, energy saving and environmental protection. Due to the equalization effect of the error,  a relatively low manufacturing precision can be used to obtain a higher guiding accuracy. Usually with servo drive, the sensor forms a closed-loop system for high-precision displacement positioning. At present,  air-floating guide rails have been widely used in measuring instruments and precision machinery;