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The discrete element boundary parameters have an important influence on the simulation accuracy. In order to improve the simulation accuracy, big urea particles were taken as the research object, the macroscopic phenomenon of the repose angle which reflected stacking process of granular particles was chosen, and the Plackett-Burman screening test was used to select the factors which was important based on the angle of repose. The order of importance for determining the effect was the rolling friction coefficient between urea particles, the static friction coefficient between urea particles and the static friction coefficient between particles and ABS plates, and the three boundary parameters influencing the accumulation of urea particles, the angle of repose was increased with the increase of the three boundary parameters. The static friction coefficient, the static friction coefficient between particles and ABS plate and the coefficient of rolling friction between particles were studied by selfmade static friction coefficient measuring instrument and virtual simulation calibration method, respectively. And the simulation and test verification of accumulating process of determined values were carried out. The relative error between the simulation repose angle and the actual test repose angle was only 0.36%. The relative error between the calibrated simulation repose angle and the actual test repose angle with different water contents was not more than 3.25%. The test results verified the validity of the boundary parameters and the simulation model. A new method for calibrating urea particle simulation boundary parameters was proposed. The validity of the calibrated discrete element model and boundary parameters of the urea particles was improved. The calibrated discrete element model and boundary parameters of the urea particles and calibration method can be applied to the dynamic simulation of the fertilizer distributor.