The invention discloses an Al-Si-SC series welding wire for laser welding of a high-strength aluminum alloy. The welding wire comprises the following chemical components in percentage by weight: 11 to 13 percent of Si, 2.0 to 4.5 percent of Sc, and the balance of Al and other inevitable impurity elements, wherein the inevitable impurity elements are Fe, Zn, Mn and Mg; the weight percentage of the impurity elements is as follow: 0 to 0.8 percent of Fe, 0 to 0.2 percent of Zn, 0 to 0.15 percent of Mn and 0 to 0.1 percent of Mg. The welding wire has the advantages that welding hot cracks can be effectively inhibited, crystal grains are remarkably refined and equiaxed, and the comprehensive mechanical properties of a welding joint are greatly improved.