In this study, a new theoretical model considering interfacial thermal resistance, pores and the shape of particles comprehensively was proposed based on the integral average method together with parallel and series model to quantitatively understand the effective thermal conductivity of particulate composite materials. The finite element simulation was utilized to demonstrate our theoretical model for that the experimental data reported in the literature were not rich enough to verify it. It is shown that the larger particles imply the smaller interfacial thermal resistance and the higher effective thermal conductivity. The thermal conductivity decreases with the increasing of porosity. Furthermore, the effective thermal conductivity of SiCpAl composites will increase when the shape factor increases and/or the particles volume fraction increases, more obviously with the larger volume fraction. After comparisons with numerical simulation and experimental data for PPS/CaCO3 and SiCpAl composites, it can be seen that our theoretical model can reach a good agreement with available numerical and experimental data.