Abstract: As key component of large square baler, frame plays vital role in supporting main strucute and connecting various functional modules．Its structural stability directly affect machine's overall service performance and working efficiency．Furthermore, frame's design rationality not only directly impacts baler functionality, but also has an important impact on machine's safety and reliability．Based on ANSYS Workbench, a static finite element analysis was conducted on large square baler．Force cloud map and deformation cloud map analysis showed that frame experienced a maximum strain of 1.255 mm at bottom crossbeam of compression chamber, while deformation in other parts was minimal．ANSYS and Solidthinking Inspired were used to perform frame topological optimization, resulting in a total mass reduction of 433.1 kg．Research findings provide a reference basis for large square baler optimization design．