To investigate the influence of meso-structure of polymer bonded explosive(PBX) on the effective elastic modulus of PBX, several meso-scale numerical models were analyzed and compared by finite element method, including hexagonal particle models, circular particle models in different particle distributions and irregular polygonal particle models established by Voronoi method. Results indicate that particle shape and distribution have remarkable influences on the effective modulus of PBX. Voronoi numerical model can not only achieve the high filling degree(>85%)of particle for PBX material, but also the meso-structure of PBX can be better resembled by irregular polygonal particle. Young′s modulus predicted by Voronoi model is 1.41 GPa, which is close to the experimental value. With increasing the particle content, Young′s modulus, bulk modulus and shear modulus increase in approximate exponent, while Poisson′s ratio decreases rapidly.