The invention relates to a method for extracting ferric oxide from tailings and belongs to the field of metallurgy. The method for extracting the ferric oxide from the tailings comprises the following steps that a, chemical treatment is conducted, specifically, the tailings and sodium hydroxide are mixed and subjected to a melting reaction for 35-85 min at the temperature of 360-590 DEG C; b, washing and filtering are conducted, specifically, reaction products are washed up through water with the temperature of 30-45 DEG C and filtered to obtain modified ores; c, ore grinding is conducted, specifically, the modified ores are subjected to ball milling for 1-5 min and screened with a wet screen of 200 meshes, and the screened-down ores are taken; and d, magnetic separation is conducted, specifically, the screened-down ores are prepared into ore pulp with the mass concentration being 20-50%, magnetic separation is conducted under the magnetic-field strength of 0.5-6 A, and iron concentrate is obtained. Through the method for extracting the ferric oxide from the tailings, the tailings can be effectively subjected to separation and enrichment, so that ferric oxide of a certain grade is obtained, and the TFe grade can reach about 68%.