为了抑制杂散光对中红外平面光栅光谱仪系统成像质量的影响，首先探讨了系统杂散光的来源，设计了遮光罩、挡光环和里奥光阑；然后针对用挡光板消除光栅衍射杂散光能力有限的问题，提出利用百叶挡光板和杂散光收集器组合来抑制杂散光的影响，并结合三维建模软件Solidworks和杂散光分析软件Tracrpro对系统进行了建模、分析和对比；最后针对某一型号红外热电堆阵列探测器并运用黑体辐射理论对其进行计算和分析，最终结果表明：光谱仪系统地气杂光抑制水平PST可以达到10-11，内部杂散辐射抑制能力有效发射率为1.3%，满足中红外平面光栅光谱仪系统杂散辐射的抑制要求。

In order to suppress the effects of stray light radiation on imaging for mid-infrared plane grating spectrometer system. First, the sources of stray light for spectrometer system were investigated, the baffle, vane and Lyot stop were designed. Then a new method of combining shutter barrier and stray light collector was proposed to solve the shortage of using normal light barrier to suppress the higher order diffraction stray light, and Solidworks and Tracepro softwares were used to model, analyze and compare the system. Finally, the sytem using an infrared thermopile array detector according to blackbody radiation theory was calculated and analyzed. Final analysis results show that the Point Sources Transmittance of the spectrometer can reach the level of 10-11, effective emissivity is 1.3%, two results show that the stray light suppression can meet the requirements.