The disclosure relates an Al—Mg series aluminum alloy sheet, a preparation method and use thereof. The preparation method includes: step S1, melting and casting the alloy raw materials in sequence to obtain an aluminum alloy ingot; step S2, subjecting the aluminum alloy ingot to a two-stage homogenization treatment so as to obtain a homogenized aluminum alloy ingot; and step S3, subjecting the homogenized aluminum alloy ingot to hot rolling, primary cold rolling, intermediate annealing, final cold rolling, and finished product annealing in sequence to obtain the aluminum alloy sheet.