Abstract: In order to improve the performance of corn stubble harvester, the finite element analysis and mode test were conducted，and the first 20 frequencies and corresponding mode shapes were obtained. The results showed that there was a torsion deformation of the screening conveyor device in the first to the fifth (8.5-29.6 Hz)modes, and there was a bend torsion deformation of beam and principal axis in the sixth to the fourteenth (44.1-124 Hz)modes, and there was also a bend torsion deformation of the tip of components in the fifteenth to the twentieth(135-190 Hz),which could be used to analyze the vibration characteristics of the machine and optimize the mechanical system.