The layered double hydroxides (LDHs) were prepared on 6061Al alloy by in-situ synthesis. The effects of LDHs on the corrosion behavior of 6061Al alloy in 3.5wt% NaCl solution with different dissolved oxygen (DO) contents (1~16 mg/L) were analyzed through the polarization curves (Tafel) and electrochemical impedance spectroscopy (EIS). The results indicate that the polarization processes of 6061Al and LDHs/6061Al alloys are controlled by DO diffusion. With increasing the DO content, a large number of pits appear on the 6061Al alloy surface, and the pit is gradually deepened. The corrosion current is increased from 1.273 μA to 1.743 μA, and the pit depth is increased from 12 μm to 19 μm. However, no pits can be observed in LDHs/6061Al alloy at different DO contents, which is attributed to the inhibition of DO diffusion and the polarization process. In addition, the resistance of 6061Al alloy is increased with increasing the DO content, which is related to the formation of Al₂O₃. However, the resistance of LDHs/6061Al alloy has no obvious change at different DO contents, showing excellent isolation performance against DO.