杂散光对光学系统的成像质量有严重的影响。从杂散光的定义出发，分析杂散光的来源，建立评价杂散光对系统影响的主要指标和点源透过率、杂散辐射比的数学模型，用TracePro对Fabry-Perot干涉成像光谱仪的杂散光进行分析和计算，通过在系统中增加遮光光栏能有效抑制系统中的杂散光，有效降低杂散辐射比。采用分析结果对Fabry-Perot干涉成像光谱仪的光机系统进行消除杂散光设计。

Proceeding from the definition of the stray light, the source of the stray light was analyzed since the stray light affects the image quality of optical systems seriously. The leading indicator adopted to assess the effect of the stray light on the optical systems, and the mathematic model of point source transmittance and stray radiation ratio were established. The stray light of a Fabry-Perot interference imaging spectrometer was analyzed and calculated with TracePro. It is found that the stray light in optical systems can be effectively restrained and the stray radiation ratio can be effectively reduced by adding a diaphragm in the systems. The optical and mechanical system design of Fabry-Perot interference imaging spectrometer was performed by the aid of the analysis result to eliminate the stray light.