Directional sowing of maize, i.e. the tip of seeds in the soil should be in the same direction and so does the embryo side, can improve crop yield. In order to realize the embryo side orientation of maize seed, an embryo side orientation device of maize seed based on vibration sorting was developed. The selector and orientor set on the spiral track of the device were innovated, the principle of embryo side orientation was proved, and the dimension parameters and space position of the selector and the orientor were determined. The optimum working parameters of the device were optimized by the test method. The experiment was employed through the method of Box-Behnken orthogonal rotating center combination of three factors and three levels. In test, dent corn seed was selected as experimental material. Combining with extensive pre-experiment and theoretical analysis, the output voltage of the controller, the vertical distance between the end point of the first orientor for turning over and the side wall and the vertical distance from the end point of the first orientor for turning over to the track surface were taken as main influencing factors, and the success rate of the embryo side orientation was taken as response index. The optimal combination of parameters was as follows: the output voltage of the controller was 101V, the vertical distance between the end point of the first orientor for turning over and the side wall was 4.38mm, and the vertical distance between the end point of the first orientor for turning over and the track surface was 7.96mm. Under the optimal combination of parameters, the success rate of the embryo side orientation was 94.85%. The verification test was repeated three times. And in the verification test, the success rate of the embryo side orientation was 94.82% with the discharge rate of 85 per minute. The actual test results were in agreement with the optimization results. In order to verify the adaptability of embryo side orientation device to different varieties of maize, the variety adaptability test was carried out, and the test results showed that the success rates of the embryo side orientation of two varieties were greater than 91%, which indicated that the device can meet the requirements of design. The research laid a foundation for the development of device for mechanized directional sowing of maize, and provided a reference for the subsequent production of seed tape of directional sowing of maize.