Abstract: The corrosion behavior and mechanism of 6A02 aluminum alloy wiring board for substation current transformer in coastal industrial environment were studied by the methods such as scanning electron microscope observation, X-ray diffraction and electrochemical analysis, combining with the analysis of actual service atmospheric environment. The results show that the intergranular corrosion of the aluminum alloy wiring board mainly occurred, and then evolved gradually into the uniform corrosion. The corrosion products were mainly composed of aluminum sulfides and chlorides. Cl^- and sulfides in atmosphere reduced the corrosion potential and increased the corrosion current density of the aluminum alloy wiring board, which were the main factors causing the corrosion failure of the aluminum alloy wiring board.