Abstract: Open compression style was used in forage press-bundle machine designed. By a group of levers part-bundle mechanism, the continuous compressed pasture was packaged into small bundles, so as to carry and store them. Compression mechanism controls lever-group part-bundle mechanism, which ensures the falling of falling-board when compression piston reaches return position, thus the mechanism makes full use of permitted maximum falling-board time; eject utensil makes falling-board time shorten by 21.7%, it improves effectively safety and reliability of operation. Movement between part-bundle mechanism and compression mechanism is simulated by MATLAB/SimMechanics software model, and structure design is improved further. Bundle ties consumption reduces simultaneously by about one third, and designed forage press-bundle machine is put into practical use.