In view of high center of gravity and poor stability of traditional corn harvesters, a corn combine harvester frame is designed for hill and mountain operations based on TRIZ theory. The frame supports engine mode of middle engine rear drive, consisting of a front frame and a rear frame. The tail of the front frame is welded under the head of the rear frame. The front frame has reduced height and increased width to allow lower center of gravity and better stability of the whole machine. The left and right longitudinal beams of the front frame have different heights to allow better trafficability of the whole machine. A 3D model is established using Solidworks software and incorporated with ANSYS software to perform finite element analysis and modal analysis on the frame. It turns out that under full-load bending and full-load torsion conditions, the frame strength and stiffness meet the mechanical performance requirements, and the frame displays fine dynamic characteristics. According to the analysis results, the frame is optimized under the goal of light weight. While the frame strength and stiffness requirements are met, the frame mass is lowered by changing the frame component thickness. After optimization, the entire frame volume is reduced by 14.27%, with mass reduced by 14.3%, and the strength and stiffness conform to the requirements, thus achieving lightweight optimization of the frame.Moreover, The stability analysis of the corn combine harvester shows the overturning angle of uphill is 45.3°, the overturning angle of downhill is 45.7°, and the overturning angle of slopel is 40.2°.