To obtain the parameters of different soil in the maize field tillage layer, the typical soil of the maize field tillage layer was divided into ordinary soil (PT) that was not in contact with maize stubble and soil (GT) that combined with maize stubble to form a root-soil complex. The discrete element parameters were calibrated by combining physical experiments and discrete element simulation. Based on Hertz-Mindlin (no slip) contact model, a four factor and five level simulation test was conducted with the central composite design of experiments method and the soil accumulation angle as the target value. Based on the Hertz-Mindlin with bonding model, the Plackett-Burman test, steepest climbing test and Box-Behnken test were designed by using Design-Expert software. The significance parameters were optimized with soil hardness as the target value, and the optimal solution combination for PT was obtained as follows: normal stiffness per unit area was 4.37×107N/m3, shear stiffness per unit area was 1.46×107N/m3, critical shear stress was 3.24×105Pa. The optimal solution combinations for GT as follows: normal stiffness per unit area was 5.19×107N/m3, shear stiffness per unit area was 4.25×10.7N/m3, and critical normal stress was 4.52×105Pa. A soil direct shear validation test was conducted based on the parameters calibrated for two types of soil. The results showed that the relative error of maximum shear stress between the simulation and measurement of the two types of soil was less than 10%, indicating that the simulation parameters were reliable. The soil particle modeling method and calibration method proposed as well as the calibrated parameter values were accurate and reliable, and can provide a theoretical basis for the construction of soil models in maize fields.