The invention discloses iron-vanadium-chrome abrasion-resistant alloy and a preparation method thereof and belongs to the field of preparation of abrasion-resistant materials. Electric-furnace smelting is adopted, medium-chromium cast iron is smelted in an electric furnace into molten iron, and the molten medium-chromium cast iron comprises, by mass, 3.8%-4.0% of C, 8.5%-9.0% of Cr, 2.1%-2.4% of Mn, 1.0%-1.2% of Ni, 0.8%-1.0% of Mo, 1.6%-1.8% of Nb, 0.5%-0.8% of Si, 0.035%-0.065% of Al, S smaller than 0.04%, P smaller than 0.04% and the balance Fe; when the temperature of the molten medium-chromium cast iron rises to 1,620 DEG C to 1,645 DEG C, ferrovanadium particles are added; and when the temperature is reduced to 1,430 DEG C to 1,455 DEG C, molten metal is poured into a mold. A box is opened to take out a casting after two to four hours after the casing is cast, the cast is placed in the furnace to be heated to 180 DEG C to 210 DEG C for stress relief treatment after grinding and sand removal, and the iron-vanadium-chrome abrasion-resistant alloy with high hardness and good abrasion resistance can be obtained.