The invention discloses a method for recovering and utilizing aluminum-containing waste sulfuric acid, and belongs to the technical field of joint recovery and utilization of aluminum-containing waste acids and solid wastes. The method utilizes the waste iron slag discharged during the steel making process to react with aluminum-containing waste sulfuric acid to reduce the sulfuric acid content in the waste acid, wherein the sulfuric acid content can be reduced to 1% or less, and aluminum oxide and iron oxide in the waste acid are recovered at the same time. The method comprises the following steps: utilizing a rotary evaporator to process aluminum-containing waste sulfuric acid until the sulfuric acid content exceeds 70%; adding waste steel slag into the condensed aluminum-containing waste sulfuric acid according to a certain solid/liquid ratio, wherein the aluminum-containing waste sulfuric acid is measured by volume (mL), and the waste steel slag is measured by weight (g); controlling the operation temperature in a range of 50 to 100 DEG C, and the reaction time in a range of 1 to 3 hours; recovering the hydrogen gas generated during the reaction process, burning the hydrogen gas to provide a heat source for the reactions; and then subjecting the reaction product to processes of solid/liquid separation, joint impurity removing, crystallization, and burning so as to obtain aluminum oxide solid and iron oxide solid; wherein the filter slag generated in the solid/liquid separation process can be mixed with the waste steel slag according to a ratio of waste steel slag to filter slag of (1-10): 1, and thus circulation utilization is achieved. The method utilizes the waste steel slag generated during the steel making process to process waste aluminum-containing waste sulfuric acid, processes wastes by using wastes, and achieves the joint treatment and resource recovery of liquid wastes and solid wastes.