Manufacturing method of aluminum alloy thin plate with stable performance

The invention relates to a manufacturing method of an aluminum alloy plate and particularly relates to a manufacturing method of an aluminum alloy thin plate with stable performance, which solves the problems that the performance of a product is not stable due to the limitation caused by a casting method and poor strength of an aluminum alloy thin plate caused by coarse tissues of magnesium alloy as cast condition. The method comprises the steps of firstly, melting; secondly, casting; thirdly, evening fire; fourthly, rolling and fifthly, annealing. According to the manufacturing method, a reasonable technical process is selected, and the purpose that the tissues are refined and the strength is improved are achieved by controlling a working rate when the product is rolled; the purpose that the performance of the plate is stable is achieved by controlling the annealing temperature; and according to the produced aluminum alloy thin plate product, the plate surface is smooth, the thickness is uniform, the surface smoothness is good, the performance is stable, the yield strength is 358MPa-367MPa, the tensile strength is 280MPa-291MPa, and the percentage elongation is 11%-15%. The aluminum alloy thin plate with stable performance manufactured by the manufactured method is used for fields of ship industries and automobile industries.