Abstract: When a boat tractor works in a paddy field, its driving force mainly comes from the interaction between the driving impeller and the soil. In this paper, curved blades are used to optimize the driving efficiency of the impeller and reduce the power loss during the traveling of the ship-type tractor.And a discrete element simulation model of the arc-shaped blade-soil is constructed.By comparing the soil force（propulsion force and supporting force） received by the arc-shaped single impeller under different central angles, thicknesses, and driving surface inclination angles, as well as the relationship between the arc-shaped blades with different parameters and the soil flow during the operation. Taking the impeller drive efficiency as a reference index, the parameters of the arc blade are optimized. The research indicates that when the central angle is 18°, the thickness is 8 mm, and the driving surface inclination angle is 6°, the traction efficiency of the blade reaches the maximum 61.23%, which is 31.11% higher than the original straight blade.It is 8.49% more efficient than the straight-face blade optimized by the research team in the previous stage, and the impeller traction performance has been significantly improved.