In view of the problems such as large loss of mechanical harvesting of edible sunflowers, seeds skin easy scratching in transporting of sunflower discs and seeds seriously broken in threshing, a threshing device was added to the traditional cutting header, and a combined harvesting cutting header device was designed which integrated the functions of dividing, lifting grain, reel, cutting, transporting and threshing by the biomechanical characteristics of edible sunflower, planting mode and requirements of mechanical harvesting of edible sunflowers. The edible sunflower discs were threshed on the cutting header, which effectively shortened path of sunflower discs transport and laid the foundation for the subsequent improvement of cleaning quality. In order to reduce the loss of cutting header, a no-row reel was designed according to posture of edible sunflower plant during the maturity period. A divider with a side inclination angle of 30° was designed, while the soft brushes were added between adjacent divider to collect the collision splashed seeds. To reduce seed breaking in threshing, an axial flow spiral drum type threshing device was designed. Based on the kinetic and kinematic analysis of material throwing process, it was concluded that the sunflower discs entered threshing device more smoothly when the inclination angle of the screw conveyor switch-plate was determined to be 18°. In order to verify the feasibility of the design of cutting header structure, field experiment was conducted. The results showed that the combined harvester could meet the requirements of sunflower harvesting with a stubble height of 700mm and five different speed conditions in the range of 1.21~2.11m/s. The loss rate was no more than 3%, the un-threshing rate was no more than 2% and the breaking rate was no more than 3%. The research result can provide technical reference for the research and development of combined sunflower harvesting machinery and equipment.