Abstract: Throwing device is an important factor that directly affects the performance of chaff cutter. For the problem of low throwing efficiency and residue blockage of disc knife chaff cutter, scholars at home and abroad have done a lot of research, but most of the previous research is based on simulation and experimental research. For the movement of materials, theoretical analysis studies are rarely performed. Most scholars only analyze the movement of material in the throwing device separately, and ignore the influence of the front-end device and airflow on the material. Therefore, this study aims to establish a more complete theoretical analysis model to provide a theoretical basis for the design of the whole machine of the chaff cutter. A kinetic analysis method was proposed to reveal the laws of material throwing motion of the disc knife maize. Material movement process were divided into seven stages in the whole throwing process, according to the matching between the throwing device and the front-end device, and the influence of airflow on the material. The movement and force of the material were analyzed in each stage. The kinetic model of the material movement along the throwing blade, along the throwing straight and elbow, and after throwing out of the outlet was established, using the initial and final velocity of each stage to connect adjacent stages. Based on the dynamic model, the throwing distance of the material was taken as index value, and a numerical calculation model was established using MATLAB software. The parameters related to the maize straw material involved in the simulation and calculation process, including moisture content, mass and diameter, were measured by physical tests. The airflow velocities in the throwing tube at different working conditions were measured using a TSI9565 anemometer, and the average value (0.203) of the coefficient of friction between the maize straw material and the tube wall was obtained using a CNY-1 inclinometer. The parameters of simulation model were determined according to the actual structural parameters of the 9Z-6A disc knife chaff cutter and the test data related to the maize straw material, and the influence of the spindle speed and blade inclination angle on the throwing performance was analyzed. The results showed that the throwing distance increased approximately linearly with the increase of the spindle speed during the test range. The throwing distance first increased and then decreased, with the blade inclination angle increased. The maximum throwing distance was obtained when the length of the shredded material was 12 mm, the blade inclination angle is 7° and the spindle speed was 700 r/min. The results obtained from the throwing distance test were consistent with the trend of the theoretical simulation results, with a maximum relative error of 6.6%, which verified the accuracy of the dynamic model. The findings can provide a theoretical basis for the structural design, parameter optimization, and matching of the chaff cutter.