It′s a hotspot to study the IR imager′s saturation and jamming effect by a laser with proper wavelength.Jamming experiment and analysis are introduced in the paper.The laser is a pulsed CO₂ laser with a wavelength of 10.6 μm.The IR imager is a 320×240 FPA uncooled imager.Laser was transmitted onto a diffuse plane,the laser was reflected to the imager.By adjust the density of the laser and process the image recorded by the imager,the saturation threshold was tested.By a general analysis,the laser power needed to jam a IR imager in a certain range was calculated.