In view of the fact that the dielectric separator could not be used in seed processing in China because of lack of specialized electrode, based on studies on electrode material and electrode construction, a new electrode was designed, with aluminum as conductor and two layers of insulation. Polyethylene was used as inner insulation material to provide insulation and polyvinyl chloride was used as the outer insulation material to protect polyethylene and provide insulation as well. Cylinders made from three electrodes with different sizes were used to test the separation effect on wheat and millet seeds. Experiments show that "whether small seeds or large seeds, the cylinder with the smallest size electrode shows the best separation effect", which provides the scientific basis for design and application of the electrode.