Preparation methodof T6-state aviation 7075 aluminum alloy coated skin thin plate

A preparation method of a T6-state aviation 7075 aluminum alloy coated skin thin plate comprises the following steps that 1, after a coating material and a cast ingot are attached, the distance between the periphery of the coating material and the edge of the cast ingot is 20-30 mm, and 7075-state aluminum alloy serves as a welding material to be fixedly welded every 1000-1500 mm in the length direction; 2, heating and hot rolling are conducted on a coated cast ingot formed by welding the coated material obtained in the step 1 and the cast ingot; 3, the hot-rolled plate with the thickness ranging from 7.0 mm to 7.5 mm is subjected to 2-3 times of cold rolling till the thickness ranges from 1.60 mm to 3.25 mm; 4, the cold-rolled plate is subjected to heat preservation for 2 h at the temperature of 370-380 DEG C, and cooling is conducted; and 5, after annealing is completed, at the temperature of 465-470 DEG C, heat preservation is conducted for 30-60 min, quenching and cooling are conducted, the plate is fed i