The contact shape, size and stress of thrust ball bearings are simulated with taking 1/13 part of bearing as finite element model, neglecting the influence of cage and lubrication, imitating the boundary curve with high order element, meshing the top and bottom raceways with sweep and the ball with free meshed by finite element software ANSYS in the contact area for the effective and exact designing of thrust ball bearing. The simulation results are corresponded to the results of Hertz’s contact theory. There are less margins for error between main dimensions except the shortest axis of an ellipse. More important will be obtained from the simulation on finite element software which cannot be derived from the traditional theory. It could improve the designing efficiency of thrust ball bearing.