Understanding the excluded volumes of particles has a great impact on the assessments of continuum percolation and random packing of soft/hard particle systems. The excluded volumes of convex particles have been extensively studied. However, little attention has been paid to the excluded volumes of non-convex partides. In this study, we propose a numerical scheme to investigate the excluded volumes of realistic three-dimensional (3D) non-convex particles. In this numerical scheme, we first reconstruct realistic particles by using X-ray tomography and spherical harmonic series. Subsequently, we triangulate the surfaces of realistic particles and detect the contact between adjacent particles by applying hierarchical detection strategies. Moreover, we present Monte Carlo simulations to obtain the excluded volumes of 3D non-convex particles. Finally, the dependence of the dimensionless excluded volumes on the roughness of surface texture and sphericity of non-convex particles is investigated. The statistical results can be further drawn into assessing the random packing and percolation properties of hard/soft 3D non-convex particle systems. (C) 2019 Elsevier B.V. All rights reserved.