The invention provides a wide-width high-
nickel cupronickel thin soft strip and a preparation method. The wide-width high-
nickel cupronickel thin soft strip comprises the following components in percentage by
mass: 30.0-32.0% of Ni, 0.6-1.0% of Fe, 0.6-1.0% of Mn, less than 0.03% of C, less than 0.01% of S, less than 0.01% of P, less than 0.01% of Pb, less than 0.01% of Zn, less than 0.01% of Si, less than 0.01% of Sn, less than or equal to 0.3% of impurities and the balance of Cu. The preparation method comprises the steps of component design,
smelting,
casting, saw
cutting, primary heating, primary hot rolling, secondary heating, secondary hot rolling, surface milling, rough rolling, trimming, bell furnace annealing heat treatment, primary finish rolling, primary
air cushion furnace annealing heat treatment, secondary finish rolling, secondary
air cushion furnace annealing heat treatment and finished product detection. The thickness of the high-
nickel cupronickel finished thin soft belt prepared by the preparation method is 0.3-1.0 mm, the width is larger than or equal to 620 mm, and the high-nickel cupronickel finished thin soft belt is stable in performance, good in extension performance, good in
corrosion resistance and capable of meeting use requirements.