Disclosed　is　a　process　for　heat　treating　Er-containing　high　Mg　content　aluminum　alloy　cold-rolled　sheet　with　inter-granular　corrosion　resistance,　　which　is　in　the　field　of　non-ferrous　metal　technology.　The　weight　percent　of　each　component　in　the　Er-containing　high　Mg　content　aluminum　alloy　hot-rolled　sheet,　　respectively,　　is　Mg　5.8%-6.8%,　　Mn　0.4%-0.8%,　　Er　0.15%-0.25%,　　Zr　0.15%-0.25%,　　inevitable　impurities　content　＜4%,　　and　the　balance　being　Al.　The　alloy　hot-rolled　sheet　is　subjected　to　cold　finish　rolling　after　intermediate　annealing,　　and　the　final　cold　deformation　is　75%-90%;　　the　aluminum　alloy　cold-rolled　sheet　is　subjected　to　stabilizing　annealing,　　with　the　annealing　temperature　being　235°C-245°C,　　and　the　temperature-maintaining　time　being　3.5-4　hours,　　and　then　air-cooled　to　room　temperature.　The　present　process　does　not　markedly　reduce　the　strength　of　the　alloy,　　but　instead　improves　the　inter-granular　corrosion　resistance　of　the　alloy.