Preparation method for high-magnesium aluminum alloy O-state plate of 5XXX series

The invention relates to a preparation method for a high-magnesium aluminum alloy O-state plate of 5XXX series. The method comprises the steps of smelting, refining, casting, soaking, saw cutting, surface milling, preheating, hot rolling, cross-cutting and uncoiling or edge trimming, saw cutting, packaging and warehousing and the like. According to the preparation method, the high-magnesium aluminum alloy O-state plate of the 5XXX series is prepared through a new production process, under the condition that the performance and structure stability of high-magnesium aluminum alloy are maintained, the production procedures can be reduced, and surface quality defects of the high-magnesium aluminum alloy can be reduced; products can be directly produced after the aluminum alloy plate with the thickness being equal to or larger than 3 mm is subjected to hot rolling, the product yield can be substantially increased, and production efficiency can be improved sufficiently.