介绍了GiresTournois镜的基本结构，运用薄膜光学理论计算了GiresTournois镜的色散，分析了各个组成部分对GiresTournois镜性能的影响.结果表明：高反射膜堆的选择影响GiresTournois镜的反射率性能，高反射膜堆的周期数取值在20~30之间能得到较理想的GiresTournois镜设计性能；GiresTournois腔的厚度影响GiresTournois镜的色散性能，GiresTournois腔的光学厚度通常选择为四分之一中心波长的2或4倍，部分反射膜堆的结构影响GiresTournois镜的色散性能，部分反射膜堆的周期数应小于5.

Basic structure of GiresTournois mirror is described and the dispersion performance is calculated. The factors affecting the performance of the GiresTournois mirrors are discussed. The results show that the layer number of high reflector affects the reflectance of the GiresTournois mirrors but the thickness of the GiresTournois cavity and the layer number of the top reflector affect the dispersion performance of the GiresTournois mirrors; to achieve good design performance, the layer number of high reflector, the thickness of the GiresTournois cavity and the layer number of the top reflector are selected to be 40~60, λ/2 or λ and less than 5.