离散元法（DEM）常用于工程尺度下颗粒系统的模拟，但计算效率仍是大规模颗粒系统运行的制约因素。现有的粗粒化处理方法适用性有限且缺乏普适的理论基础。为解决此问题，研究利用量纲分析描述精确缩尺系统中物理量的缩放定律，通过代表性体积单元 (RVE)，在粗粒化系统和原始系统之间建立了质量、动量和能量的近似守恒关系，并获得了2个不同尺度（宏观和细观）下相应物理量的缩放关系。为验证所提出的双尺度粗粒化离散元方法的正确性，将该方法应用于煤散料下落和回转试验中，真实试验中煤颗粒尺寸为4 mm，仿真中采用5组不同缩放系数的煤颗粒，其尺寸范围为4～12 mm，试验与仿真中煤散料总体积均为0.001 m³。煤散料下落试验采用平均冲击力和堆积休止角作为对比指标，结果表明，随着煤颗粒尺寸增大，两者的相对误差总体呈现增大趋势（尺寸为12 mm时，冲击力误差为14.36%，休止角误差为19.05%）。煤散料回转试验采用上试样受力和煤散料堆积轮廓曲线相关系数作为对比指标，结果表明，随着颗粒尺寸增大，相对误差随之增大，相关系数总体降低（尺寸为12 mm时，受力误差为39.29%，相关系数为0.957 4）。仿真所需时长比预测时长还要少，结果充分证明了双尺度粗粒化离散元法的有效性，粗粒化系统在可接受的误差范围内可显著提高计算效率。

The discrete element method (DEM) is commonly used for simulating particle systems at the engineering scale, but computational efficiency remains a limiting factor for large-scale particle system simulations. Existing coarse-grained methods have limited applicability and lack a universal theoretical basis. To address this issue, this study utilizes dimensional analysis to describe the scaling laws of physical quantities in an exact scaled system. By using representative volume elements (RVE), approximate conservation relationships for mass, momentum, and energy are established between the coarse-grained system and the original system. Scaling relationships for corresponding physical quantities at two different scales (global and particle level) are obtained.To validate the correctness of the proposed two-scale coarse-grained DEM method, the method is applied to the falling and rotation tests of bulk coal. The particle size in the actual tests is 4mm, while in the simulations, five groups of coal particles with different scaling coefficients ranging from 4 mm to 12 mm are used. The total volume of bulk coal in both the tests and simulations is 0.001 m³. The falling test of bulk coal uses the average impact force and the reposeangle as comparative indicators. The results show that as the particle size of coal increases, the relative errors of both indicators generally increase (at a particle size of 12 mm, the error in impact force is 14.36%, and the error in the reposeangle is 19.05%).The rotational test of bulk coal uses the correlation coefficient between the applied force on the upper sample and the profile curve of the bulk coal heap as a comparative indicator. The results show that as the particle size increases, the relative error increases, and the correlation coefficient generally decreases (at a particle size of 12 mm, the force error is 39.29%, and the correlation coefficient is 0.9574).The simulations require less time compared to the predicted duration, fully demonstrating the effectiveness of the dual-scale coarse-graining DEM method. The coarse-grained system can significantly improve computational efficiency within an acceptable range of errors.