The role of friction was concerned when analyzing the interaction between spiral lifting component of sugarcane harvester and the sugarcane for establishment of a friction-helix model for sugarcane convection. Combined friction coefficient measurement with lifting test, the condition escaping the dropping of sugarcane during the lifting process was discovered. The results showed that the friction coefficient of sugarcane without leaves was less than that of sugarcane with leaves, and it took 6.5 s for lifting of the sugarcane without leaves, during which the sugarcane dropped 2~3 times. While for sugarcane with leaves, it took only 4.5 s for lifting, and the sugarcane seldom dropped. Thus the lifting effect was more outstanding for sugarcane with leaves than that for those without leaves.