Abstract: Harvesting forage is a very important part of the forage production process. Realizing the mechanized harvesting of forage is of great significance to ensure the efficiency of the entire forage production process and has great time guarantee for subsequent forage processing. The self-propelled forage harvester designed this time follows the principle of simplicity and efficiency. The rotary cutter is equipped on the header part, which is suitable for all kinds of forages, especially suitable for thick, easy to fall forages. The work is stable and the work efficiency is high; during the cutting process of the forage, it is not easy for the forage to block the cutting blade, and it is easier to replace the cutting blade.