The invention relates to the production methods of smelting in electric furnaces and horizontal continuous casting in the technical field of ferrous metallurgy, in particular to a method for smelting 07Cr2MoW2VNbB steel in an electric furnace and using the same to form round pipe billets through horizontal continuous casting. The method comprises the steps of raw and auxiliary material proportioning, smelting in the electric furnace, ladle refining, vacuum degassing and horizontal continuous casting. At the earlier stage of smelting, the slag with strong oxidability and good mobility is manufactured and rapid dephosphorization is carried out at low temperature. At the later stage of smelting, rapid heating, high boiling, degassing and inclusion removing are carried out to improve the cleanliness of molten steel. Tundish and a crystallizer are in sealed butt joint during horizontal caster production and protecting slag is unnecessary to be added into the crystallizer, thus omitting a link of secondary oxidation and slag inclusion absorption of the molten steel. Water spray and cooling are not needed after the casting billets exit from the crystallizer. Combined electromagnetic stirring of a secondary cooling zone and a solidification end is adopted to improve the quality inside the casting billets. The casting billets do not have bending processes and do not need to be flattened, thus being beneficial to production of the steel containing vanadium and niobium. The method is low in production cost and ensures the billet yield of the steel to be improved by over 5-10% compared with arc continuous casting and die casting.