The invention provides a production method of aluminum oxide for coating titanium dioxide, and relates to a production process method of the aluminum oxide for coating the titanium dioxide. The production method is characterized in that in a production process, a sodium aluminate solution produced in a production process of the aluminum oxide is adopted as a raw material, and hydrogen peroxide is added into the sodium aluminate solution as an oxidant; the sodium aluminate solution is subjected to de-coloring treatment. According to the method provided by the invention, the oxidant is added, so that low-valence metal in the solution is oxidized to generate sediment; the sediment is removed from the solution, so that the chroma of the solution is reduced; then the solution is used for coating the titanium dioxide. A preparation process flow of the sodium aluminate solution with low impurity content can be shortened, and the coating cost of the titanium dioxide is reduced.