The invention discloses a production process for a steel casting of martensitic wear-resistant steel. The martensitic wear-resistant steel comprises the chemical components by the weight percentage: 0.3%-0.5% of C, 0.4%-0.9% of Si, 1.1%-1.8% of Cr, 0.8%-1.5% of Mn, 0.7%-1.2% of Ni, 0.6%-0.8% of Mo, 0.2%-0.5% of V, 0.1%-0.5% of Ti, 0.07%-0.09% of Re, not more than 0.04% of P and S, and the balance being Fe. The production process comprises the following steps: 1) scrap steel, pig iron, ferrochrome, sponge iron and a smelting additive with an amount of 1-1.5% based on the total mass of the above raw materials are added to an induction furnace for mixing and heating to melt, wherein the smelting additive is prepared from 10-15 parts of sodium oxide, 3.5-4.5 parts of aluminum oxide, 3-5 parts of potassium oxide, 6-8 parts of sodium carbonate, 4-6 parts of silicon dioxide, 11-15 parts of iron oxide, 0.5-2 parts of titanium dioxide, and 5-10 parts of anhydrous borax, and the contents of the chemical components are adjusted according to requirements. Under a condition of relatively low shock, the martensitic wear-resistant steel is applied in ball mill lining plates of metallurgical mines, hammerheads of hammer mills and the like, is applicable to wear-resistant products of gold mines, iron mines, cement and other types of mines, and is a new wear-resistant material instead of conventional high manganese steel.