A forging method for producing a 21-10Mn7Mo welding wire and a blank forged by the method belong to the technical field of welding, relate to the production of a solid welding wire used for gas-shielded arc welding, a forging method, a component forged by the method and a hot-rolling technology and further relate to a steel ingot and the smelting thereof. The forged blank comprises the following chemical components in a percent by mass: smaller than or equal to 0.10 of C, smaller than or equal to 0.8 of Si, 5.5-8.0 of Mn, smaller than or equal to 0.030 of P, smaller than or equal to 0.020 of S, 9.0-11.0 of Ni, 19.0-22.0 of Cr and 0.5-2.0 of Mo, wherein the ratio of Mn to Mo is controlled between 7 and 7.5. The forging step adopted for producing the forged blank comprises the step of heating a blank, and forging temperature is controlled in a way that initial forging temperature is higher than or equal to 1180 DEG C and final forging temperature is higher than or equal to 850 DEG C. The smelting step of a forged steel ingot comprises the technical step of using an electric-arc furnace return oxygen blowing process to smelt an electroslag re-melted electrode.