Abstract: As an important performance index of infrared warning-reconnaissance system, operating range was usually assessed by the dynamic flight test in open air range. However, the dynamic flight test merely evaluated operating range under the typical weather conditions. Because of this, an equivalent calculation method based on the digital image injection simulation test was proposed, which could evaluate the operating range of IR warning-reconnaissance system under different weather conditions. Then, the test mode of the digital image injection simulation named as film-replay was presented, the generation method of digital image using for the equivalent calculation of operating range was described in detail, and a simulation test instance was realized to prove the validity and precision of the digital image injection simulation method.