Abstract: In the process of discrete element numerical calculation, the establishment of the particle model is an important factor to affect the accuracy of the simulation.It is necessary to establish the 3-D models of irregular grains for discrete element method whose morphology is approximate to the real grain to analyze and simulate the main working process like precision seeding and precision selecting and classifying seeds.At present, an irregular particle with complex contours is simplified into the regular shape to model, which can lead to reduction of the simulation accuracy. In order to improve the accuracy of the dynamic simulation of the irregular particles, a method of modeling 3-D DEM models was proposed for irregular shape particles like rice grain based on 3-D laser scanning.Five hundreds of Kongyu 131 (rice cultivar) rice seeds were chosen randomly and scanned using CF-30 automatic high precision 3-D scanner.The size distribution of length, width and thickness is in accordance with the normal distribution and the average length, average width and average thickness of the three-dimensional measurement were 7.0 mm, 3.5 mm and 2.4 mm, respectively.The rice seed with the average three-dimensional sizes was scanned and the polygonal contour model and space coordinate information were obtained by the process of treating color, noise removal, point cloud registration, point cloud triangulation, consolidation and model modification using the reverse engineering software Geomagic Studio.The polygonal contour model was imported into SolidWorks and the 3-D DEM model with complex contour of the rice seed based on 3D laser scanning was created by inverse modeling.The 3-D DEM model of the rice seed based on 3D laser scanning was filled by 87 balls particles based on the theory of polymer particles, which was named as Model1.The 3-D DEM model of the rice seed with the same three-dimensional sizes as Model1 was processed usually as regular ellipsoid, which was named as Model 2.In order to test the simulation accuracy for discrete element method of the modeling method of irregular particle based on 3D laser scanning, the simulation prediction of repose angle for Model 1 and Model 2 was done respectively using the discrete element method software EDEM.The repose angle of the Model 1 and the Model 2 were 29.77° and 27.08°, respectively.And the repose angle of the actual rice seeds was measured under the same condition as the simulated experiment condition for comparative analysis.The experimental result of the repose angle was 29.70°. And the measurement errors between the simulation results by two modelling methods and the actual experiment value about repose angle were 0.24% and 8.83%, respectively.The repose angle obtained by Model 1 based on 3-D laser scanning was closer to not only the experimental measured value but also accumulation form, and there was a big error between that by Model 2 based on the usual treatment as regular ellipsoid and the experimental result, which showed that the modeling method of irregular particle for discrete element based on 3-D laser scanning was validated and available.This paper provides a new means to improve simulation precision of irregular particles for discrete element method.