To improve the work efficiency and stability of discharger in soybean conditioner, this paper combined the discrete element method to simulate the motion process of soybeans in the discharger, and analyzed the effects of rotor blade number, feeding plate angle, and angle between inlet and outlet of the discharger. The results showed that when the velocity of discharger was 12 r/min, the number of rotor blades had a significant negative correlation with the discharger’s work efficiency and stability. The feeding plate angle had no significant on the work efficiency and stability, but it would cause material residue at the inlet of discharger. The larger the angle between the inlet and outlet led to the lower the work efficiency of discharger, but the work stability was better. The above research showed that when the number of the rotor blades was 6, the feeding plate angle was 40°. The angle between inlet and outlet was 180°, and the work efficiency and stability of discharger reached optimal levels.