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Combined with the previous related background of intergranular corrosion of 6 series, 2 series, and 7 series aluminum alloys, highly effective rectification plans under different failure scenarios can be sorted by priority.: The precise composition control plan controls the Cu content of the 6 series alloy to ≤0.4%, optimizes the Cu and Zn element ratio of the 2/7 series alloy, adds trace amounts of Mn and Cr to refine the grains, and reduces the active precipitation phase at the grain boundary from the root, which is the most fundamental and effective means of long-term corrosion resistance. The over-aging/dual-stage aging heat treatment scheme adjusts the T6 peak aging to T73 over-aging or dual-stage aging, so that the grain boundary precipitated phase changes from a continuous network to a discrete granular form, which can improve the intergranular corrosion resistance level of the 2/7 series alloy to the optimal N level, taking into account both strength and corrosion resistance. The overall pickling process optimization plan is for 7 series aluminum alloys. It uses a mild pickling formula of phosphoric acid + low nitric acid, strictly controls the chloride ion content, and is equipped with low-temperature short-time operation + post-sequential passivation sealing, which can completely eliminate intergranular corrosion induced by the pickling process. The rapid quenching process improvement plan requires immediate water quenching after solution treatment to avoid staying in the sensitization range of 300-500°C, which can prevent the Cu/Zn-rich phase from segregating at the grain boundaries and greatly reduce the intergranular corrosion sensitivity of 6-series extruded profiles. Among the above solutions, the combined solution of composition control + overaging heat treatment has the highest comprehensive effectiveness and can cover the intergranular corrosion failure rectification needs of most industrial scenarios.