Abstract: Closed-loop simulation based on digital image injection is an effective testing means of IR imaging guidance weapon countermeasure and complicated environment adaptability, it collects frame angle of seeker and real-time simulates to generate IR image when the detector of IR seeker is replaced by image simulation computer and injection device, the image is injected by injection device. The principle of closed-loop simulation test were analyzed, software, hardware platform and work scheduling of simulation test system were designed, miss distance time delay and miss distance error were calculated, consistency analysis platform of simulation test and actual work was built, yaw and pitching angle velocity error and homing precision were analyzed by miss distance time delay and miss distance error. The result shows that the condition of simulation test and actual work of seeker was consistent, simulation test system was scientific. The research results provide theoretical support for developing closed-loop injection simulation test.