Abstract: In order to reduce the damage of sugarcane during harvesting and improve the harvesting efficiency of sugarcane harvester, this paper analyzes the damage to sugarcane caused by the knockdown roller during harvesting by sugarcane harvester based on finite element method, and the stress analysis of cutting area of sugarcane harvester shows that there are different stresses at cutting point and sugarcane-soil interface.When the sugarcane harvester is not equipped with a knockdown roller, the irregular movement of the sugarcane during the cutting process causes the stress between the sugarcane to be greater than its yield limit and is prone to breakage, resulting in incomplete cutting.The knockdown roller can significantly reduce the stress at the cane-soil interface, reduce the movement between canes and improve the quality of sugarcane cutting.