Abstract: Based on the combined finite-discrete element method (FEM-DEM), the tensile fracture of zirconia toughened alumina particle reinforced Fe45 composites(ZrO₂-Al₂O₃/Fe45) was simulated using axisymmetric representative volume elements. The mesh sensitivity of FEM-DEM models was analyzed. The results show that the second-order solid elements coupling double zero thickness cohesive elements FEM-DEM model reduces the mesh sensitivity. The tensile fracture simulation results of ZrO₂-Al₂O₃/Fe45 show that particle shapes have a great influence on the crack propagation. The crack of ZrO₂-Al₂O₃/Fe45 initiates at the interface which is perpendicular to the direction of tension force, then matrix crack occurs when the interface crack extends to the stress concentration position of the matrix. The cracks of the composites consist of the interfaces crack and matrix crack.