Abstract: Using superelasticity material model taking plasticity into consideration and quasi-brittle material model based on damage plasticity, a three-dimensional finite element unit cell model was established, and the monotonic tensile behaviors of shape memory alloy particle toughening bulk metallic glass matrix composites were simulated. The effects of mechanics parameters and volume fraction of shape memory alloys, along with interface thickness and interface material parameters on the toughening of bulk metallic glass were discussed. Results show that the increasing of the phase transformation strain of shape memory alloys and martensite plastic yield stress can improve the tensile failure strain of shape memory alloy particle toughening bulk metallic glass matrix composites significantly; meantime, the tensile failure strain changes little when the elastic modulus of shape memory alloys is beyond 50.0 GPa and martensite plastic yield stress is over 1.8 GPa. The reasonable volume fraction of shape memory alloy in balance of failure strain and failure stress is about 15%. The increasing of composites interfacial elastic modulus and interfacial yield stress can improve the failure stress of composites; however, the failure strain does not change a lot with them. The increasing of the thickness of composites interface can improve the failure strain while decreases the failure stress of composites.