The invention discloses a method for removing aluminum impurities in an iron-containing mixed solution of sulfuric acid and phosphoric acid. The method comprises the following steps that (1) a certainamount of reducing agent and neutralizing agent are added into the mixed solution; (2) non-oxidizing gas is fed into the solution at a certain temperature, and thermostatic water-bath stirring is conducted; and (3) filtering is conducted after stirring is conducted for a period of time, and obtained filtrate is the impurity-removing solution. The method has the advantages that the process is simple, the flow path is short, the aluminum impurity removing effect is good, no impurity is introduced, and the method is suitable for large-batch production.