Abstract: The wide application of metallic glass is limited by its poor room temperature plasticity. Therefore, improving the mechanical properties of metallic glass and exploring the deformation mechanism of metallic glass have become the research hotspot in the field of materials. The effects of grain size and distribution on the mechanical behavior of dual-phase nanocrystalline/amorphous B2-CuZr/CuZr composites were studied by molecular dynamics method. The results show that with the increase of the size of nanocrystalline particles, the deformation mode of the composites changes from relatively uniform deformation to local deformation of single shear band. The results also indicate that the peak stress of the composites can be effectively increased by increasing the size/volume fraction of nanocrystals, but the plasticity of the composites is not significantly enhanced except for the smaller size nanocrystalline model. In addition, alignment of nanocrystals leads to more severe plastic strain localization than cross alignment. The results of this paper have important reference value and guiding significance for the design and preparation of high-performance metallic glass materials.