The method is to determine the spectrum distribution character of the workpiece surface and the processing parameter. It analyzes the making error of the optical element from the spatial frequency spectrum especially the character and the quantity relation between the high frequency error and the processing parameter. Then the error data of the optical element get from the testing device is treated by the information processing technology, it determines the relation of the processing parameter and the spectrum distribution character using the one dimension power spectral density ratio as the evaluating indicator. The invention provides a new method to determine the processing parameter in the optical element surface process, so it is important for making the high quality optical element. |