In order to reduce the problem of low cleaning performance of oats cleaning device, the structure of single fan three cylinder screen cleaning device was improved according to the physical characteristics of oats, and a cylinder screen oats cleaning device with arc grid screen re-cleaning was designed. A skip plate structure was installed on the large cylinder screen, which can make the material jump up and fully separate. The arc grid baffle screen and re-cleaning parts was designed and installed to reduce the impurity content and the entrainment loss. Based on the performance parameters of traditional single fan three cylinder screen cleaning device, the cleaning principle and function of skip plate of large cylinder screen and arc grid baffle screen was analyzed theoretically. Taking the rotating speed of centrifugal fan, the rotating speed of large cylinder screen and the angle of arc grid baffle screen as the experimental factors, and the impurity content and loss rate of oat grain as the experimental indexes, the indoor ternary quadratic orthogonal rotation combined test was carried out. The results showed that when the rotating speed of centrifugal fan was 1500r/min, the rotating speed of large cylinder screen was 110r/min, and the angle of the arc grid baffle screen was 41°, the cleaning effect of the device was the best, the impurity content rate was 1.96%, and the loss rate was 2.64%. A field test was carried out. Under the optimum parameters, the impurity content rate was 1.97%, and the loss rate was 2.68%, which provided a reference for the optimization of the structure of the oat cleaning device and the improvement of the whole structure of oat combine harvester.