Abstract: In order to improve the design of bucket elevator and reduce the damage in the transportation process, three soybean varieties (Liaodou 15, Liaodou 18 and Heinong 40) were used as the samples. TD250 bucket elevator was involved in the soybean injury test of the ascension delivery, and the soybean mechanical damage characteristics and mechanism were studied. The results showed that the mechanical damage rate of transportation process by soybean bucket elevator was about 10%. Damage characteristics mainly contained broken, two discs, defect and skin damaged. Damage rate of skin damaged was the most among the damage characteristics, about 7.5%. Mechanical damage was mainly caused by shear force, friction and impact pressure made by dust pan, and impact reaction force produced by soybean hitting the machine cover under unloading. Damage rate was reduced at 6.7% after loading and unloading structure and operating parameters optimization.