介绍了太阳模拟器的组成及工作原理。在非成像光学的光学扩展量基础上,对照明系统和投影成像系统进行了光学匹配,并从拉赫不变量的角度分析了能量在整个系统中的传递情况,得出椭球聚光镜、光学积分器和准直物镜这三者的相对孔径相互之间的最佳匹配关系,即三者的相互之间的相对孔径值均为1/4时，满足光瞳衔接原理。计算得到了从物面到像面的拉赫不变量为045，验证了整个光学系统从物面到像面的拉赫不变量守恒,有效地利用了光学系统的光能。

This paper introduces the composition and operational principle of solar simulators. Based on the extence concept of non-imaging optics, the whole system including an illumination system and a projection imaging system are matched, and the energy transfer in the whole system is analysed on the basis of Lagrange invarian. The best matching relationship of relative aperture 1/4 among the ellipsoid condenser, optical integrator and the collimated object lens are obtained and satisfies the pupil connected principle. This calculated value of Lagrange invariant is 045, which verifies that the Lagrange invariant is conserved from an object surface to an image surface. So the optical energy of the optical system is used effectively.