To meet the high accuracy optical testing requirement, the absolute measurement technologies instead of traditional testing techniques are more and more used in optical testing. However, the traditional absolute measurement technology has its own scope and complexity of the experimental process which required experimental equipment with high precision. In the filed of only rotationally asymmetric surface error required, rotating average method is a simple absolute measurement technology. Rotating average method is applied to rotationally asymmetric surface error testing of plane, spherical and aspheric. The principle of rotation averaging method was introduced. Then optical design software was used to simulate the testing process of rotation averaging method. By simulation test, the shape of the rotation asymmetric error and the kNθ rotation error were analyzed, simulation results in good agreement with theoretical results. Simulation experiment results show that rotating average method can effectively improve the testing precision of rotational asymmetric surface shape and the experimental simulation model can effectively simulate the actual testing process.