High-rigidity and high-strength aluminum alloy welding wire

The invention discloses a high-rigidity and high-strength aluminum alloy welding wire. The high-rigidity and high-strength aluminum alloy welding wire comprises, by mass, 5.0-6.0% of Mg, 0.5-0.8% of Mn, 0.1-0.2% of Ti, 0.15-0.25% of Cr, 0.1-0.2% of Zr, 0.05-0.1% of B, 0.15-0.25% of V, at most 0.4% of Fe, at most 0.4% of Si, at most 0.1% of Cu, at most 0.2% of Zn, at most 0.10% of other single impurity elements which each accounts for at most 0.05% and the balance Al. When the welding wire is used for welding a 5A06 aluminum plate with the thickness being 4 mm through a manual argon tungsten-arc welding method, the tensile strength of a welding joint can reach 330 MPa and reach 89% of the strength of base metal, and the elongation at break can reach 13.5%. The fatigue strength feature value, corresponding to the survival rate of 95%, of the welding joint under the condition of 2*106 circulation times can reach 40 MPa.