The finite element method of design of the vehicle frame of sugar cane planter based on 3D solid element is introduced. The stress and strain of the vehicle frame when bearing bending loads and bending-torsion loads are analyzed. The frame strength and stiffness under over loading condition are discussed and the suggestions for design improvement are presented and primal frame have been optimized, the strength and stiffness of new frame structures are examined and the reasonable lightweight design is achieved.