In order to improve the accuracy and stroke of a precision positioning stage, a new precision pneumatic servo positioning stage was designed. The metal bellows were used as an independent driving device in this system, and the air bearing sliders were designed by finite element method (FEM). The motion stage was supported by air bearing slider, and the high precision with large stroke was studied under the condition of without friction. The mechanical characteristics of bellows were analyzed, and the system parameters were identified in connection with the experimental data to establish the hysteresis curves of preloading. The threshold and power values of basic hysteresis operators were determined, and the system hysteresis model based on PI model was established, and the model was verified. Saw-toothed wave on the changing rate of 0.5 V/s and 5 V/s were used in the experiments in connection with the established model. The experimental results show that the system hysteresis model is a very good approximation to the system output. In the case of open-loop, errors between the model output and the system output are less than 10 μm on the slow rate signal input, and are no more than 20 μm on the fast signal input. Its performance can reach the accuracy requirements of the high-precision positioning stage.