When the screw conveyor conveys white kidney beans, the motor drives the screw blades to rotate in the sealed material trough. The thrust of the screw is used to overcome the friction between the material and the trough, allowing the white kidney beans to move along the axial direction. The sealed structure prevents sprouting. Horizontal or inclined conveying methods can be set as needed to stably transport white kidney beans to designated workstations such as processing and storage.