The invention relates to a method for performing vanadium increase and refining in vanadium alloying by utilizing vanadium-containing slag and is used for solving the problem of reducing the production cost of smelting vanadium-containing steel. When the vanadium-containing steel is produced by the method, according to the vanadium content of the steel, the vanadium-containing slag of a convertoris added into an LF furnace in a refining process for vanadium alloying, wherein the increase amount of vanadium for the alloying of the vanadium-containing slag in the LF furnace is controlled to bebetween 0.005 and 0.050 percent and the use amount of the vanadium-containing slag is controlled to be within 10 kilograms per ton of steel; and the addition amount of the vanadium-containing slag ofeach ton of steel is determined by a vanadium slag addition amount formula of each ton of steel under the condition. The method utilizes the partial or total vanadium-containing slag with low price to substitute vanadium-containing ferroalloy, breaks through a traditional production process flow of using alloy micro-alloying in an initial steelmaking furnace or in the tapping process, and transfers a vanadium element alloying link to the refining process of the LF furnace. The vanadium-containing high-strength steel produced by adopting the method can remarkably reduce the production cost on the basis of reaching relevant standard requirements on components and performance.