There are some problems in the practical application of multi-function forage kneading machine, such as easy blockage and throwing distance can not meet the requirements of use, which are related to the coupling movement characteristics of material and air in the machine. In order to explore the coupling motion law of material and air flow in the kneading machine, the coupling model of air flow and loose material in the process of material crushing was established by using the coupling method of computational fluid dynamics (CFD) and discrete element method (DEM), and the coupling motion law between material and air flow was numerically simulated. The accuracy of the coupling model and numerical calculation was verified by airflow velocity test and throwing distance test. The results showed that the relative errors between the simulated and measured values of the outlet airflow velocity were within 8.1%. The relative error between the numerical calculation and the measured value of the average throwing distance of the material at the three speeds within the rated speed range was less than 5%, which verified the accuracy of the coupling model and the numerical calculation results. After the forage materials were broken, they moved circularly along the wall of the crushing room and were thrown out of the machine along the discharge pipe. After the kneading machine was stable, the maximum speed of indoor particle movement always fluctuated up and down at a certain average speed, and the average speed reflected the kinetic energy obtained by the material particles under the impact force of the hammer. The larger the kinetic energy of the granular material was, the less likely the device was to be blocked, and the farther the average throwing distance of the material was. The research provided a basis for optimizing the coupling motion characteristics of material and air flow in the kneading machine, avoiding clogging and increasing the throwing distance of material.