In order to improve the wear resistance of surfacing layer of 4043 aluminum welding wires, Mg and Sr were added based on the chemical composition of traditional 4043 aluminum welding wires and the surfacing layer from obtained Al-Si-Mg-Sr welding wires were heat treated. The effects of Mg, Sr and heat treatment on the wear resistance of the surfacing layer were studied. The results show that the morphology of eutectic silicon particles could be changed by Sr and the strengthening phase Mg2Si appears with the addition of Mg. Meanwhile eutectic silicon particles are spheroidized and their binding ability with the matrix is intensified after the reasonable heat treatment. Therefore, Sr, Mg and heat treatment improve significantly the wear resistance of the surfacing layer together.