The invention discloses a method for preparing high-grade titanium slag by taking vanadium titano-magnetite as a raw material. The vanadium titano-magnetite is subjected to direct reduction-smelting separation to generate smelting separation titanium slag containing TiO2 with a mass percent of greater than 60%. The invention belongs to the technical field of metallurgy. According to the method disclosed by the invention, the rough concentrates of the vanadium titano-magnetite are subjected to fine grinding, selection and deep impurity removal, pelletizing is carried out by virtue of an organic binder, pellets are dried and then subjected to reduction roasting to obtain metallized pellets, the metallized pellets generate the smelting separation titanium slag by virtue of high-temperature smelting separation of an electric furnace, and then the smelting separation titanium slag is subjected to magnetic separation iron removal to obtain the high-grade titanium slag. The method disclosed by the invention is capable of increasing the grade of the titanium slag, provides the high-quality raw material for the subsequent preparation for titanium dioxide through sulphuric acid, and has the characteristics of saving cost and reducing pollution.