compare the internal structure;choose the following 2 dimensions for design options: linear curvilinear dimension and verticak-tiled dimension of the rear contour of harvester (fig.4),and then build the 3D modeling by software. the R&D enterprise should elect 20 persons from its sale apartment,customers and engineers to from a jury, this jury should evaluate the final product according to the rotatable 3D models and final renderings. the evaluation result suggested that those large globoidal curves and the curviinear rear contour shoukd be combined togethr, then desing a new moeling based on this,the initial program acceptedis fig.4-5