Abstract: To improve the mechanical properties and corrosion resistance of vacuum die-cast aluminum alloys for new energy vehicles, the electrochemical corrosion behavior of as-cast and heat-treated alloys in different concentrations of NaCl solution were studied by means of cryogenic+solution+aging heat treatment strengthening method, and through comparative analysis with unheat-treated as-cast alloys. The results show that the corrosion resistance of vacuum die-casting aluminum alloy is significantly improved after cryogenic+solution+aging heat treatment. Compared with the as-cast alloy, after heat treatment, the grain of the α-Al phase is refined, the grain boundaries are increased and diffusely distributed, and a uniform microstructure is formed, which effectively reduces the local electrochemical corrosion caused by the potential difference. Secondly, the Si phase is round and evenly distributed, and the tip of the Al₅FeSi phase is passivated and the size reduces, so that the stress concentration reduces, which is not conducive to the invasion of chloride ions.