Abstract: The model of chaff motion is established on the basis of considering the influence of the space atmospheric density,velocity and damping coefficient on chaff and combining chaff self attribute and motion trait.Based on the applied situation of deploying the air jamming corridor,the formation scenario and diffusion model of the chaff curtain wall is established,and the related parameters,length,width,thickness,drift velocity,bulk density,and tropism of the chaff,are described quantificationally.Simulation instance shows this model can reflect the law of chaff motion,which can offer the applied basis for the research of chaff jamming and anti-jamming.