[en] 7 series high-strength aluminum alloy work pieces got massive corrosion before assembling in summer. The number of corrosion shows increasing trend year by year, which has an impact on relevant departments' production tasks. We analyzed possible causes of 7 series high-strength aluminum alloy work pieces rust from mechanical working, cleaning procedure, assembling environment, metallographic image, electron spectrum and relevant experiments. The result showed that the surface of aluminum alloy work pieces got CL residue. CL residue can crack the oxide film on aluminum alloy under the high humidity environment in summer, which leads to rust. However, we can prevent this rust of 7 series high-strength aluminum alloy work pieces effectively by using pure water to blend cutting fluid and reducing the humidity of environment. (authors)