The invention relates to the technical field of flyknit uppers, in particular to a three-proofing flyknit upper. The method comprises the steps that 1, a flyknit fabric is taken to be subjected to vapor pressing forming to obtain a flyknit upper; 2, the flyknit upper is subjected to air-drying; 3, the surface of the flyknit upper is coated with a waterproof breathable coating. After vapor pressing, air-drying is performed, damage caused by vapor pressing to the fibre structure is avoided, the waterproof, anti-siphon and anti-oil-stain functions can be recovered under anhydrous vapor, and thenthe waterproof breathable function is enhanced by coating the waterproof breathable coating.