Because of two kinds of deformation with tool under general process of tillage, i.e., bending deformation with straw extrusion and shear deformation with straw shear, at loading speeds of 15~30mm/min, and also on two different positions of straw for measuring the displacement in the soil, which was horizontal and vertical with down-rotary speeds of 180~280r/min with the help of color straw labeled and arranged in lines and paralleled to the rotor axial. The original and final positions of straw tracers were drawn with Matlab software. It was found that the shape of final positions was similar to the arrangement of rotary blades attached to the rotor. The results revealed that the bending strength of wheat straw was decreased with increase of loading speed, and that of rice straw was increased at initial stage and then decreased with the increase of loading speed. It was obvious that the shear strength of rice straw was increased, and for wheat straw it was also increased at initial stage and then decreased with the increase of loading speed. The comparisons and conclusions of experiment were drawn as follows: the displacement and fluctuation of rice straw were greater compared with those of wheat straw, and the straw arrangement mode was corresponding through two types of straw distribution, the coordinate position of vertical straw and horizontal straw was symmetrically distributed on the X axis and X and Z axes, respectively. Based on these findings, the rotational speed of 230r/min can be chosen，meanwhile，adjusting the operation type and straw arrangement in the field can help to achieve a good effect of straw returning to field.