The rapid development of entire-process-vacuum high pressure die casting (HPDC) technology provides the possibility for the industrial application of bulk metallic glasses (BMGs), which has received widespread attention. However, the room-temperature brittleness of BMG is still one of the biggest stumbling blocks limiting the application of BMG parts in some key fields. To overcome this problem, in this paper, 304 stainless steel skeletons were introduced into Vit1 BMGs by HPDC technique under high pressure and with large filling rate to create BMG/stainless steel composites. Furthermore, the effects of stainless-steel volume fraction on the microstructure and mechanical properties were studied systematically. The results showed that the stainless steel skeleton in the HPDCed composites was uniformly distributed in the metallic glassy matrix and displayed metallurgical interface with the Vit 1 BMG. The mechanical properties test indicated that the plasticity of the brittle Vit1 BMG was significantly improved with the introduction of stainless steel skeleton. As the mesh number of stainless steel increased (corresponding to the increase of the volume fraction of crystalline phase), the plasticity of composites displayed an increasing trend. However, when the mesh number exceeded 200, there were some deteriorations in mechanical properties due to the unfilled porosity defects in the composites. When the volume fraction of crystalline phase is about 53.7%, the fracture strain of composites reaches the maximum value of about 10%, which is much higher than that of Zr-based BMG composites toughened by traditional stainless steel fibers. The analysis of the toughening mechanism showed that the brittle-ductility transition of the HPDCed Vit1 BMGs mainly resulted from high efficiency suppression of shear band propagation by metal skeleton, which promotes the proliferation and initiation of shear bands and reduce the localization of macroscopic plastic deformation, as well as the reduced stress concentration due to decrease of mesh number. This study provides new insights for the design and preparation of BMGs composites with excellent mechanical properties, and has important engineering value for application of BMGs.