The infrared radiation characteristic of the target is one of the important infrared data for stealth performance evaluation and target recognition.The traditional infrared radiation inversion technology categorizes the targets into point targets and surface targets for processing respectively. Considering the influence of the flight attitude and range variation of the target, it is difficult to categorize the targets into point targets and surface targets by using the present infrared radiation characteristic data. A general method for measuring infrared radiation characteristics is proposed in this paper， which can unify the processing of target characteristics and simplify the data processing mode. In this paper, the accuracy of target inversion is verified by using this method based on the measuring system of medium wave infrared radiation characteristics of 600 mm caliber. The target data is processed respectively under the conditions of 2000 μs and 3000 μs integration time, which proves the effectiveness of the proposed algorithm. This method has certain engineering application significance.