Abstract: An axial permanent magnetic bearing is designed by selecting the combination of type a1 of basic configurations of axial PMB. Considering that this bearing only produces axial displacement and has the axis-symmetry structure, so it could be simplified into an axis-symmetry 2-D plane model for studying. Then, using ANSYS to make magnetic force calculation about 1/2 model and the influence of the width, thickness, section area and gap of both stator magnetic ring and rotor magnetic ring on the axial bearing capacity and axial stiffness is acquired. In the end, through contrastive analysis, some useful conclusion are obtained which is the optimization basis for physical design of this type of axial PMB. It has certain guiding significance for engineering application.