Abstract: Abstract: To enhance the mechanization level of potato cultivation and promote the development of potato industry, we research and design a cup-belt type seed-metering device of potato seeder. This potato seed-metering device is mainly aimed to solve many problems, including the high multiple index and missing index, heavy manual labor intensity, poor universality and other problems commonly occurring in the widely used potato seed-metering device at present. This paper introduces the main structure, the working principle and the related structural parameters of the device in detail. In this paper, we design the structure of many key components. The arrangement form of scoops on the belt, the working principle and the structure of the vibrating cleaning device, and the structure of the active belt pulley and the arch breaker are analyzed through the theoretical analysis. The parameters obtained from the theoretical analysis are used to design the cup-belt type seed-metering device. The actual utilization indicates that the seed-clearing system driven by electric motor has a simpler structure and more stable operating condition. The arch breaker increases the liquidity of the seeds and improves the filling rate. We also make a list of experiments to understand how the factors affect the performance of the potato seed-metering device and analyze the experiment results. These experiments include the overall experiment, the bench test and the field experiment. We also design an overall experiment to investigate the filling performance and the height caused by entrainment. We determine the revolving speed of the driving pulley and the number of the seeds in the seed case as the experimental factors of this experiment. The experimental results show that: when the revolving speed of the driving pulley is 33.4 r/min and the seed case is full of seeds, the average empty scoop rate is 0.33%; when the revolving speed of the driving pulley is 33.4 r/min and the seed volume is 12.5% of the seed case volume, the average height caused by entrainment is 25 cm. But even the seed case is full of potato seeds, the maximum height caused by entrainment is below the driving pulley axle. In other words, the phenomenon will not happen that the seeds are entrained into the guide pipe which causes reseeding. So when the revolving speed of the driving pulley is 33.4 r/min and the seed case is full of seeds, the working performance of the seed-metering device also meets the requirements. An orthogonal experiment is carried out in order to understand how the experimental factors affect the performance of the seed-metering device. These factors include the revolving speed of the driving pulley, the inclination of the seed-metering device and the vibration strength of the seed-clearing device. Each factor has different influence on the performance. The optimal working parameters can be concluded through these experiments and a validation experiment is carried out to verify the optimal working parameters. The experimental results show that: when the revolving speed of the driving pulley is 42 r/min, the inclination of the seed-metering device is 0° and the vibration strength of the seed-clearing device is 0.75, leading to the best performance. The qualified index is 92.6%, the multiple index is 4.5%, and the missing index is 2.9%. The field validation experiment shows that the performance of metering device under the condition can meet the potato seeder's working performance requirements. This research provides a theoretical and technical reference for the research and design of seed-metering device of potato seeder.