The infiltration casting method is widely employed for the preparation of ex-situ composite materials. However, the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses (BMGs). This work optimized the composition of Zr-based BMGs through microalloying methods, resulting in a new set of Zr-based BMGs with excellent glass-forming ability. Wetting experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method, and the interfaces were characterized utilizing a scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs melt. Additionally, the incorporation of Nb element impedes the formation of W-Zr phases, but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element, indicating that the influence of Nb element on the diffusion of individual elements is minute.