采用光的干涉方法检测曲面光学表面的加工质量时，都需要事先设计好系统光路的最佳检测技术参数，并能对检测的难度进行有效的评估，从而确保检测的精度。该研究采用了一种计算干涉条纹密度的新方法，对任意光学曲面检测的难度进行评估，并用于确定球面参考光点光源的最佳位置。以非球面为例，计算了非球面的最接近球面的半径和最大非球面度以及非球面检测时球面参考光点光源的最佳位置，说明了计算干涉条纹密度方法在确定干涉检测系统光路调试最佳条件的优越性，可为各种干涉检测系统的设计以及优化调试过程提供理论依据和分析指导。

When using optical interferometry to inspect curved optical surfaces, the best technology parameters of light path were always designed in advance and the difficulty of inspection was evaluated in order to ensure the accuracy of inspection. A new way for calculating the interference fringe density was adopted to evaluate the difficulty of inspection for any curved optical surface and to determine the best position of reference spotlight source. Taking the aspheric surface for example, the radius of the best fitting sphere of aspheric surface, the max asphericity and the best position of reference spotlight source were calculated. Result shows the superiority of the new way in choosing the best condition of adjusting the light path of optical interference system. It can provide theoretical basis and analytical guidance for the design of interference inspecting system and the optimization debugging process.