Creep-aging forming, combining both the aging treatment and forming process, has recently drawn much attention of researchers. In this study, the effects of creep-aging processing on the corrosion resistance and mechanical properties of a typical Al-Cu-Mg alloy are investigated by electrochemical corrosion, exfoliation corrosion and uniaxial tensile experiments. The results show that the corrosion resistance and mechanical properties of the studied Al-Cu-Mg alloy are strongly sensitive to the creep-aging processing parameters. The creep-aging processing can change the dimension and density of nanoprecipitates, which greatly affects the corrosion resistance and mechanical properties of the studied Al-Cu-Mg alloy. With the increase of creep-aging temperature, the corrosion resistance and the elongation decrease, while the yield strength and ultimate tensile strength increase. For the materials creep-aged in “under aging” and “peak aging” conditions, the applied stress can increase the ultimate tensile strength, but deteriorate the corrosion resistance.