The geometric model and the finite element model with the measured results for corn seed were established. The stress distribution of corn seed was analyzed under different pressing locations and different pressing loads by the finite element method. The microcosmic mechanical properties of corn seed under different pressing locations and different pressing loads were obtained, which could be provided as mechanical parameters for further studying mechanical properties and damage mechanism of corn seed and optimizing threshing machine. It could be concluded that breaking position and breaking direction of corn seed accorded to simulating result and microcosmic crack of corn seed aroused macroscopic breakage after the comparison was made with the model calculation and the experimental results.