Preparation method of medium-intensity Al-Mg-Mn-Si alloy plate

The invention discloses a preparation method of a medium-intensity Al-Mg-Mn-Si alloy plate. The preparation method comprises the following steps: (1) burdening: preparing the following element components in percentage by mass: 0.6 to 1.1 percent of Si, 0.9 to 1.2 percent of Mg, 0.05 to 0.3 percent of Cu, 0.5 to 0.9 percent of Fe, 0.6 to 1.0 percent of Mn, less than or equal to 0.10 percent and more than or equal to 0.001 percent of Ti, less than or equal to 0.4 percent of Zn and the balance of Al and one or more of the following elements: less than or equal to 0.2 percent of Cr, less than or equal to 0.05 percent of V, less than or equal to 0.5 percent of Hf, less than or equal to 0.25 percent of Sc, less than or equal to 1.0 percent of Ag and less than or equal to 0.2 percent of Zr; (2) smelting; (3) refining; (4) semicontinuous casting; and (5) aging to obtain a product. The method disclosed by the invention is low in production difficulty and efficient; the product is stable; and the method guarantees the