The relevance of the study is due to the need to reduce the energy intensity of the process of cutting sunflower stalks by choosing a rational profile of knives. The research is based on a comparative analysis of experimental values of cutting forces for the proposed and manufactured design of the knife system and known knife systems. The studies have shown that the implementation of the retaining and main knives of the header in the form of a curved spiral of Archimedes allowed to reduce the cutting force. It was also found that the cutting force for the proposed design of the knife system, unlike other studied, practically does not change with the removal of the stem from the axis of rotation of the knives, which does not require an increase in energy costs for the cutting process.