© 2022 Elsevier LtdIn this study, mechanical properties of CaCO3 reinforced Polypropylene (PP) matrix composite materials were investigated using the Digimat-Mean Field (MF) homogenization approach and ANSYS Finite Element Method (FEM). Simulation of CaCO3/PP composites, including 5, 15, 30, and 60 w% of CaCO3 was carried out by using a two-step multi-scale approach method. In the first stage, the micro-mechanic properties of the CaCO3/PP composite structures were obtained by using Digimat-MF by taking into account parameters, such as particle diameter, particle addition ratio, and interface binding between matrix and particle. As for the second stage, the Digimat interface was generated using the ANSYS Finite Element Method and macro-scale structural analyses of the CaCO3/PP composite structures were performed. In this way, the tensile and flexural strength of the CaCO3/PP composite structures were calculated by the ANSYS Finite Element Method. In addition, experimental analyses were carried out to approve the accuracy of the FEM results pertaining to the CaCO3/PP composites. The fact that the results obtained by experimental and simulation studies are very close to each other is an indicator of the accuracy of the simulation procedure applied in this study.