The invention discloses a preparing method for a high-purity nickel wire. The method comprises the steps that electrolytic nickel is selected as a raw material firstly, a vacuum induction smelting furnace with the vacuum degree capable of reaching 0.01 pa is selected as smelting equipment, a calcium oxide crucible is adopted as an induction smelting crucible, the selected raw materials are placedin the vacuum induction smelting furnace, material melting is started when the vacuum degree in the vacuum induction smelting furnace reaches 0.01 pa, and power is cut and film forming is conducted after the raw materials are completely melted; then, a deoxidizing agent is added for deoxidizing and refining, and then, the refined raw materials are poured into a cast ingot die; and then, the ingotdie is cooled under the vacuum, and after the temperature in the vacuum induction smelting furnace is reduced to 200 DEG C or below, the nickel ingot can be taken out. After cutting and grinding, rolling and wire drawing are conducted. The oxygen and nitrogen content of the nickel wire prepared through the method is lower than 10 ppm, the fluctuation error is within +/-0.5 ppm, and a high-purity nickel bag can be provided for the titanium alloy oxygen and nitrogen analysis.