To prove the efficiency of the method to measure IR radiation peculiarity of aerial target, the modeling for the IR radiation peculiarity of aerial target was built with the knowledge about the wide band IR detector in medium and long wave, the mature arithmetic is calculated on the basis of optimization theory. The modeling and arithmetic were proved very precise by the results of the ideal experiment values simulation and field test data processing. Lastly, combining field experimental phenomena and processed data, the origin of measure error of radiation peculiarity for aerial target and the method to reduce the error were analyzed.