Abstract: Based on the free volume theory and Ramberg-Osgood model, a representative volume element model with particles random distribution was established, and the microstructure effect of Ti_64.5Zr_14.5V_18.5Cu_2.5 particles toughening Ti-base metallic glass matrix composites under the uniaxial tension, was simulated by ABAQUS code. The effects of particles volume fraction, the number of reunion and aspect ratio, along with particles orientation and interface on the ductility of metallic glass were discussed. Results show that increasing particles volume fraction can improve the plasticity of composites significantly, but at the expense of the part strength of the composites. Increasing particles aspect ratio can enhance the plasticity and yield strength of composite materials. Making the orientation of particles and the load direction into 90 ° or 0°not only enhances the plasticity, but also improves the strength of composites compared with the other configuration. Reducing the number of reunion to below two can significantly reduce loss of the plasticity and strength of metallic glass composites, and the particles of reunions and the load at 90°, can improve the plasticity and strength of composites. In particles toughening metallic glass matrix composites with zero interface, particles and matrix debonding in interface in the main shear belt can be observed, according with the experimental phenomena more. The results help to well understand the microstructure effect of the composite materials which is beneficial to the design of the material.