IR imaging guided missile has been developed widely, special material decoy against it is produced. Based on the jamming theory of special material decoy, combining with operation principles and anti-jamming methods of IR imaging guided missile, on the basis of MJU-50/B special material decoy of America, the motions and infrared radiation models of airplane, IR imaging guided missile and airborne special material decoy are built. Simulation of special material decoy in spatial countermeasure is realized. And the characteristics of airborne special material decoy are summarized and analyzed.