Heat-resisting Al-Cu-Mg aluminum alloy

The invention discloses heat-resisting Al-Cu-Mg aluminum alloy, and belongs to the technical field of nonferrous metal materials and processing thereof. The technical problems that in the prior art, Al-Cu-Mg aluminum alloy is poor in high temperature resistance, and silver-doped modified Al-Cu-Mg aluminum alloy is high in cost and not suitable for large-scale production are solved. The heat-resisting Al-Cu-Mg aluminum alloy comprises, by mass, 3.5%-4.5% of Cu, higher than 1.8% but no more than 2.3% of Mg, 0.03%-0.2% of rare earth, 0.03%-0.2% of V, 0.3%-0.9% of Mn, and the balance Al and inevitable impurity elements; the rare earth is one or a mixture of La, Ce, Sm, Nd, Gd and Y, and the mixture is formed by mixing several elements according to any proportion. According to the aluminum alloy, through increase of the content of Mg, proper reduction of the content of Cu and the combined action of Al, Cu, Mg, RE and V elements, the aluminum alloy has good high temperature resistance and good plasticity.