Abstract: In order to improve the mechanization level of sunflower harvesting in Xinjiang, a flexible belt type sunflower harvesting machine is designed by imitating the working principle of manual harvesting, aiming at the problems of high labor cost and high labor intensity of inserted plate drying and sectional harvesting. The main components of the machine are a flexible belt type dish taking device that simulates farm worker manual hand dish taking and a threshing device that simulates manual knock sunflower dish. According to the analysis of the physical characteristics of the sunflower disk and the movement process of the disk, the belt width of the conveyor belt in the disk taking device is determined to be 130 mm, and the included angle between the sunflower stalk and the vertical direction is determined to be 11.7°, the diameter of threshing roller is 80 mm, and the spacing between threshing rollers is 170 mm. According to the central combination test method of Box-Benhnken, the test was carried out with the machine speed, threshing roller speed and threshing roller slip as test factors and the grain loss rate as test indicators. The results showed that the significant order of each factor to the loss rate was the speed of threshing roller, the speed of the machine, and the slip rate of the threshing roller. The optimal combination was the speed of the machine 0.32 m/s, the speed of the threshing roller 400 r/min, and the slip rate of the threshing roller 0.16. Under this parameter combination, the grain loss rate of sunflower was 2.97%. The designed machine basically met the design requirements of low loss harvesting, providing a reference for the harvesting technology of inserted disk type sunflower machinery.