The invention relates to the field of welding materials, in particular to a novel aluminum alloy welding wire and application thereof. The novel aluminum alloy welding wire comprises, by mass percent, 5.50-7.0% of Mg, 0.80-1.0% of Mn, 0.25-0.35% of Ti, 0.05-0.20% of Zn, 0.10-0.20% of Cr, 0.25-0.35% of Zr, not more than 0.2% of Fe, not more than 0.2% of Si, not more than 0.05% of Cu, not more than 0.0005% of Be, not more than 0.1% of other single impurity element, not more than 0.15% of total other impurity elements, and the balance of Al. The hydrogen content of the aluminum alloy welding wire is not more than 0.03ml/100g. The novel aluminum alloy welding wire is low in hydrogen, fine-grain, and even in internal structure. Product detecting and welding experiments show that welding seams are high in strength, high in plasticity, fine in solidification metal grains, low in thermal crack tendency, and good in corrosion resistance. The aluminum alloy welding wire is suitable for aluminum alloy section bar welding of various vehicles, aircrafts, and ships.