具有确定相对孔径的光学系统只能对有限景深范围内的物体进行清晰成像。而超出景深范围的物体经过两个光学元件的两次反射之后，聚焦于探测器靶面，形成超景深鬼像光斑，大大降低了对比度。利用Code V与LightTools软件对已产生超景深鬼像的光学系统进行了仿真分析，并对产生超景深鬼像的两个光学元件表面进行了定位。仿真结果与产生的现象能够对应，证明该方法正确可行，并可用于其他光学系统。

The optical system with the fixed relative aperture can only clearly image objects within a limited depth of field. Once reflected twice by two optical elements, the object beyond the depth of field is focused on the detector target surface， and a exceed depth of field ghost spot forms， which greatly reduces the contrast. In this paper, Code V and LightTools are used to simulate and analyze the optical system, and the surfaces of the two optical elements are located which generate the ghost image of depth of field. The simulation results correspond to the generated phenomena. It proves that the simulation analysis method is correct and feasible,and can be used in other optical systems.