A series of refractory solid welding wire with different alloy composition were designed and the contrast experiment was conducted. By means of various test methods including chemical composition test, tensile test, optical microscope and scanning electron microscope, combining the experimental results of mechanical properties and microstructure, the effect of V and Nb on the microstructure and mechanical properties of deposited metal of refractory solid welding wire was analyzed, and the relationship between the microstructure and mechanical properties was analyzed. The results show that at high temperatures the addition of V and Nb can promote dispersed precipitation of carbide, enhance the precipitation strengthening effect and the stability of microstructure, thus effectively increases the high-temperature yield strength of deposited at 600 ℃, but the addition of Nb obviously reduces the low-temperature impact toughness of deposited metal. Solid welding wire containing Mo and V can guarantee good high-temperature yield strength and favorable low-temperature impact toughness.