Column air cushion was taken as object of study. The theoretical model of the static stiffness, initial internal pressure and compression deformation were established in terms of the geometry model based on the isothermal process inside the air cushion. Static stiffness characteristics were obtained from quasi-static compression test, and comparison was made between the models and experimental values of the different specifications and initial internal pressures. The results showed that the static stiffness from theoretical model is more suitable for small compression deformation.