The invention relates to a method for preparing a low-cost centimeter-sized zirconium-base amorphous alloy by adopting industrial sponge zirconium, and relates to a method for preparing the zirconium-base amorphous alloy. In order to solve the problem that the production cost of the zirconium-base amorphous alloy is high since high-purity metal zirconium is adopted as a raw material for an existing zirconium-base amorphous alloy, the method comprises the steps of (1) weighing raw material according to the atomic percent; (2) vaccumizing an electric arc furnace, and filling a protection gas; (3) carrying out titanium smelting; (4) preparing an alloy ingot, and repetitively smelting the alloy ingot; and (5) drop casting. According to the method provided by the invention, the low-purity industrial sponge zirconium is adopted as a raw material for preparing the zirconium-base amorphous alloy, so that the production cost of the zirconium-base amorphous alloy is reduced; the method providedby the invention is beneficial to inhibiting generation of nucleation particles or eliminating impurity nucleation particles; and compared with the existing zirconium-base amorphous alloy, the zirconium-base amorphous alloy provided by the invention has the same excellent mechanical performance. The method provided by the invention is applicable to preparing the zirconium-base amorphous alloy.