This article is to describe the working theorem and composition of one kind of automatic harvesting control system for sugarcane harvesting machine. It has its own ways to control harvesting in this system, one is parameterize pre-setting function and the other is one key harvesting function, it brings several advantages of operating simplification and less working strength for driver. Moreover, this system adopts control technology to prevent transporting channel from blocking while harvesting, can effectively protect cutting blade and improve harvesting efficient.