Abstract: Radiation from shock layer near a window of an IR imaging detection system carried by an endo-atmospheric high-speed flying vehicle can degrade detection performance of the system. Single Line Group Model (SLG Model) was selected to describe radiation characteristic of the shock layer. Because the shock layer radiation was near field radiation to the imaging system, a relevant physical model was constructed to calculate photon irradiances caused by the shock layer radiation in the detector array. Absorption characteristic of the shock layer to target radiation was also calculated. Calculation results show that background radiation caused by the shock layer radiation in the detector array is nearly uniform and the target radiation absorbed by the shock layer can be neglectable. The magnitude of the shock layer radiation varies greatly with wavelength. In the imaging system, respective selection of different optical bandpass filters can change position of the working wave band of the system without changing wavelength width of the working wave band. According to the characteristics of the shock layer radiation, the change of the working wave band can mitigate the shock layer radiation effect on target detection and improve signal-to-noise ratio of target detection.