The main factors that affect the imaging characteristic of infrared imaging seeker and the jamming principle of infrared decoys on the imaging characteristic of infrared imaging seeker were analyzed based on signal transfer and conversion mechanism of infrared imaging seeker. Then, with the end-to-end imaging modeling ideas, and considering the impact of infrared decoys on the radiative properties of target surface and the auto gain characteristics of infrared imaging seeker, the imaging characteristics quantitative model of infrared imaging seeker was established. Furthermore, on the basis of theoretical analysis mentioned above, the real-time simulation of the output images and tracking features of infrared imaging seeker after infrared decoys jamming was carried out by computer 3D scene simulation technology, and the tracking performance of the infrared imaging seeker was studied based on the simulation results. The results show that the jamming effect of infrared decoys on the tracking performance of infrared imaging seeker varies with the launching direction of infrared decoys. The infrared decoys show the greatest jamming effect when the launching angle of infrared decoys are about 75°-95°、190°-215° or 250°-280°, while infrared decoys show the least jamming effect when the launching angles of infrared decoys are about10°-40°, 150°-170° or 315°- 325°.