Abstract: The effects of natural aging on the mechanical properties and electrochemical corrosion behavior of T6 state 7A04 aluminum alloy under slow rate cooling conditions were studied by tensile test, hardness test, conductivity test and electrochemical test combined with TEM and SEM. The solid solution method selected in the experiment was heated at 475 ℃ for 1 h and holding for 1 h. The quenching medium were air and room temperature water. The results show that, adding natural aging before artificial aging can optimize the microstructure and properties of 7A04 aluminum alloy, which can make the size of the precipitated phase in the crystal smaller and more uniform. Furthermore, the tensile strength, yield strength,hardness and other mechanical properties of 7A04 aluminum alloy under slow rate cooling condition are improved, and the plasticity is maintained. Meanwhile, the corrosion current density of 7A04 aluminum alloy in 3.5% NaCl solution is smaller and the corrosion resistance is improved.