To reduce losses through the header on a rape combine harvester, a disc cutter suitable for rape harvest was designed. Biophysical property of single rape was studied using pendulum impact testing machine, the results showed that the suitable height for rape cutting is 200 mm to 400 mm. Based on the self-propelled testing apparatus for rape cutting, the single factor and multi-factor orthogonal experiments were carried out on the factors that influence consuming power and factors influencing seed losses including cutting velocity, cutting height and cutting dip. The results of single factor experiments showed that when the rotating speed was 700 r/min, the cutting height 300 mm and the cutting dip 10°, 30.19 W of power was consumed and a loss of 1 162 rapeseeds was observed. The results of multi- factor orthogonal factor experiments showed that the optimal cutting parameters included rotating speed of 750 r/min, cutting height of 250 mm, cutting dip of 10°, apparatus forward velocity of 0.4 m/s and cutting blades of 6, which were similar to those observed in orthogonal test 5, and 36.39 W of power was consumed with a loss of 895 rapeseeds.