The effective interference of the accompanying infrared decoy against the infrared imaging air-to-air missile relates to the performance and usage of the accompanying infrared decoy and elusion tactic of target warcraft.Taking infrared staring focus plane array seekers as example,kinetic characteristic and radiation characteristic of the system was studied by digital modeling,and this trinity system is composed of target warcraft,accompanying decoy and infrared imaging missile.Through countermeasure simulation,the influence of decoy’s usage and target’s elusion tactic on operational effectiveness of the missile was quantitatively analyzed.Simulation results can provide some countermeasure methods for jamming the infrared imaging missiles,and it is also helpful to other similar countermeasures.