To build a general modelling method for soybean seed particles, based on an analysis of soybean seeds from different regions in mainland China, twelve representative varieties of soybean seeds are selected as the research objects. Through an analysis of the shapes and sizes of the soybean seeds for the twelve varieties, it can be seen that the shape of the soybeans across the twelve varieties can approximated to an ellipsoid, with a sphericity ranging from 80.57% to 95.42%. Additionally, both the length and the thickness of the soybean seeds for the twelve varieties have highly linear relationships with the fourth power of the width. Three varieties of soybean seeds with different sphericities (Suinong42, with a sphericity of 94.78%; Jidou17, with a sphericity of 86.86%; and Zhongdou39, with a sphericity of 80.6%) are then selected as examples. The multi-sphere method is employed to build the 5-, 9-, and 13-sphere models of one single particle as well as the assembly model for the three varieties of soybean seeds. Meanwhile, the ellipsoid model of one single particle and the assembly model for the three varieties of soybean seeds are built using the ellipsoid equation method. In addition, the multi-contact phenomenon in the multi-sphere model is also studied. The single particle model and the assembly model of soybean seeds proposed and built in this paper are analysed by comparing the simulation and experiment in both the "self-flow screening" test and the "angle of repose" test. It can be seen from the analysis results that the 5-, 9-, and 13-sphere models built using the multi-sphere method in this paper are suitable for the particle modelling of soybean seeds for different varieties, and the simulated result of the multi-sphere model is superior to that of the ellipsoid model built by the ellipsoid equation. When the sphericity of soybean seed particles is high, they can be built using the 5-sphere model; when the sphericity of soybean seed particles is low. they can be built using the 9- or 13-sphere models. Moreover, the multi-contact phenomenon has little effect on the simulated results of the multi-sphere models of soybean seed particles. (C) 2020 Elsevier B.V. All rights reserved.