Nanoparticles plugging effect has recently been recognized in shale cores. However, the motional discipline and plugging efficiency of different nanoparticles in shale pores have not been well recognized. In this paper, an approach with CFD and DEM to model particulate suspension flows is presented in the micro scale for shale pores. The particle trajectory and the plugging efficiency can be obtained through the discrete particle model. To ensure rationality, a UDF program was written to correlate the standard drag curve, based on the critical examination of available data for spheres. Results indicate particle size and concentration are main factors affecting plugging efficiency. Meanwhile, particle velocity, pores roughness and tortuosity have a major impact on plugging effect. However, particle ratio, gravity, rotation, density, shape and roughness have little effect on plugging efficiency. And the simulation results (particles sizes and concentration) are verified by theoretical formula and experimental results from the literature view, the fitness increases the credibility and applicability. The established model provides an effective method for investigating different particle release parameters. It also has a reference value for the range of variation of nano or micro particle blocking pore efficiency at the microscopic scale. (C) 2019 Elsevier Ltd. All rights reserved.