Abstract: Noise equivalent temperature difference(NETD) and signal to noise ratio(SNR) are one of the important parameters to measure performance of infrared imaging system, which is related to various performance parameters of the detector. Performance parameters of different types of infrared detectors are analyzed after laser irradiation interfering infrared detection system. Through theoretical calculation and calculation, system NETD and SNR curve before and after YAG (wavelength 1.06 μm) laser jamming are compared. NETD after laser damage is two to three orders of magnitude larger than that of pre-damage. At the same time, SNR after laser jamming is two orders of magnitude smaller than that before laser jamming. Influence of laser jamming on infrared detection system is derived.