Preparation method of 6-series aluminum alloy plate

The invention discloses a preparation method of a 6-series aluminum alloy plate. The preparation method comprises the steps of burdening, smelting, degassing and filtering, casting, homogenizing treatment, saw cutting, quenching, artificial aging and surface flatness treatment. During homogenization treatment, the temperature in a homogenization furnace is adjusted to 100-150 DEG C, a cast ingot is put into the homogenization furnace and heated to 380-440 DEG C, heat preservation is conducted for 8-12 h, then the temperature in the homogenization furnace is adjusted to 480-560 DEG C, and heat preservation is conducted for 3-6 h; during quenching, the temperature in a quenching furnace is adjusted to 560-570 DEG C, then the sliced cast ingot is put into the quenching furnace, and when the temperature of the cast ingot reaches a specified temperature, the cast ingot is subjected to heat preservation for 0.5-8 h; and then the cast ingot is cooled, and the cooling speed of the thickness center part of the cast in