The establishment of flexible corn model is a key process of the corn-harvest mechanism, which is a kind of rigid-flexible coupling multi-body system. A modal neutral file for ADAMS was created in ANSYS by meshing the stem model and defining the attach point. The model of harvest mechanism and the modal neutral file of corn stem were imported into ADAMS. The status of motion of stem was simulated by applying load, constraints, and drive. And from the simulation, the variation of location and velocity were obtained. The status of motion in the mechanism was studied.