The extent of existing corn land in Indonesia and the activities carried out by farmers in corn farming requires the innovation of an effective and efficient corn harvesting machine. This underlies the Research Center for Appropriate Technology located at the Faculty of Engineering, Universitas Negeri Padang to design a corn harvesting tractor that can facilitate the community in carrying out activities in the agricultural sector. The design of the corn harvester tractor consists of the harvester mechanism, the frame, the engine, and the powertrain. The frame is a crucial component of the corn harvester tractor, and its strength depends on its shape and proportions. The construction's strength of the frame must take into account both safety considerations and the structure's strength. The purpose of this study is to evaluate the frame strength of a corn harvester tractor made of steel of the ASTM A36 type. In this study, the von Mises stress that exists in the frame is used to calculate the strength of the frame of a corn harvester tractor. In numerical analysis, the chassis utilizes two tests with various load variations, namely the concentrated load and the load that is evenly distributed on the surface. The simulation results show that the frame of the corn harvester tractor can withstand the load well. The results of the stress analysis that occurs on the frame of the corn harvester tractor are that the maximum stress that occurs due to the concentrated load on the frame is 3.248 MPa. While the maximum stress that occurs due to the distributed load acting on the frame is 3.510 MPa. In addition, information was obtained that the value of the safety factor for the frame with ASTM A36 type met the component requirements that could withstand concentrated loads and distributed loads