A process for smelting steel for ultrafine silicon carbide (carborundum) sawing wires, comprising the following steps of: 1) melting a raw material into liquid molten steel under the protection of argon in a vacuum induction furnace, the raw material uses carbon-free pure iron and low-phosphorus pig iron having a carbon content of 3.5%-4.5% by mass; then vacuumizing to perform vacuum smelting, the vacuum smelting is performed under a condition of less than 300Pa to degas for 15-20 min, and performing deoxygenation with high-purity silicon iron as a deoxidizer to adjust components of the molten steel; and after the adjustment of the components of the molten steel, casting circular ingots under vacuum condition, wherein each ingot has a mass of 1.5-2.5 tons, a diameter of 0.35-0.4 m and a length of 2-3 m; 2) cleaning the surface of the circular ingots to manufacture electrode bars for electroslag smelting; 3) remelting and smelting the electrode bars as raw materials in an electroslag furnace, wherein an electroslag protecting slag comprises the following in percentage by mass: CaF 2 : 45-55%, Al 2 O 3 : 15-25%, SiO 2 : 20-25%, Na 2 O: 2-4%, and K 2 O: 1-2%; and smelting the electrode bar in the electroslag furnace into a cylindrical electroslag ingot having a diameter of 0.4-0.5 m; 4) forging the electroslag ingot into a forged billet for wire rolling, wherein the forged billet is a square billet having a cross section of square with a side length of 0.140-0.160 m, and the forged billet has a length of greater than 6 m; and 5) rolling the forged billet into a steel wire rod having a diameter of 4.5-5.5 mm by the wire rolling process, wherein the steel wire rod comprises the following chemical elements in percentage by weight: [C]: 0.92-1.1%, [Si]: 0.3-0.4%, [Mn]: 0.5-0.8%, [Al]: less than 0.0008%, [N]: less than 0.005%, [S]: less than 0.01%, [P]: less than 0.015 %, and the balance of iron and unavoidable impurities, 1) melting a raw material into liquid molten steel under the protection of argon in a vacuum induction furnace, the raw material uses carbon-free pure iron and low-phosphorus pig iron having a carbon content of 3.5%-4.5% by mass; then vacuumizing to perform vacuum smelting, the vacuum smelting is performed under a condition of less than 300Pa to degas for 15-20 min, and performing deoxygenation with high-purity silicon iron as a deoxidizer to adjust components of the molten steel; and after the adjustment of the components of the molten steel, casting circular ingots under vacuum condition, wherein each ingot has a mass of 1.5-2.5 tons, a diameter of 0.35-0.4 m and a length of 2-3 m; 2) cleaning the surface of the circular ingots to manufacture electrode bars for electroslag smelting; 3) remelting and smelting the electrode bars as raw materials in an electroslag furnace, wherein an electroslag protecting slag comprises the following in percentage by mass: CaF 2 : 45-55%, Al 2 O 3 : 15-25%, SiO 2 : 20-25%, Na 2 O: 2-4%, and K 2 O: 1-2%; and smelting the electrode bar in the electroslag furnace into a cylindrical electroslag ingot having a diameter of 0.4-0.5 m; CaF 2 : 45-55%, Al 2 O 3 : 15-25%, SiO 2 : 20-25%, Na 2 O: 2-4%, and K 2 O: 1-2%; and smelting the electrode bar in the electroslag furnace into a cylindrical electroslag ingot having a diameter of 0.4-0.5 m; 4) forging the electroslag ingot into a forged billet for wire rolling, wherein the forged billet is a square billet having a cross section of square with a side length of 0.140-0.160 m, and the forged billet has a length of greater than 6 m; and 5) rolling the forged billet into a steel wire rod having a diameter of 4.5-5.5 mm by the wire rolling process, wherein the steel wire rod comprises the following chemical elements in percentage by weight: [C]: 0.92-1.1%, [Si]: 0.3-0.4%, [Mn]: 0.5-0.8%, [Al]: less than 0.0008%, [N]: less than 0.005%, [S]: less than 0.01%, [P]: less than 0.015 %, and the balance of iron and unavoidable impurities, <EOS>