In order to better apply the discrete element method to study the mixed sowing process of oat and arrow pea seeds and improve the accuracy of the seed discrete element model, the simulation parameters were calibrated combined with the actual test and simulation test. The intrinsic parameters of oat and arrow pea seeds were measured by sampling, and the seed discrete element model was established. Collision test, inclined plane sliding test and inclined plane rolling test were used to calibrate the collision restitution coefficient, static friction coefficient and rolling friction factor between seeds (oat seeds and arrow pea seeds) and ABS plastic plate, respectively, and oat and arrow pea seeds were obtained. The collision recovery coefficients with ABS plastic plates were 0.441 and 0.435, the static friction coefficients were 0.506 and 0.454, and the rolling friction coefficients were 0.059 and 0.047, respectively. Based on the stacking test, using the steepest climbing test and quadratic regression orthogonal rotation combination test method, and taking the relative error between the edem simulation value and the actual value of the stacking angle of mixed seeds as the index, the interspecific collision recovery coefficient, static friction coefficient and rolling friction coefficient were determined to be 0.320, 0.327 and 0.042, respectively. The calibration results were verified by the screw seed transmission device. The average relative error of the mixed seed mass flow rate between the simulation test and the actual test was 1.76%, and the average relative error of the seed transmission mass ratio of oat and arrow pea seeds was 2.03%. The reliability of the simulation test was verified. The calibration results can be used in the discrete element simulation test of the mixed sowing process of oat and arrow pea seeds.