The process optimization of rutile titanium dioxide coated with Al2O3 was realized via orthogonal experiment. The structure and performance of the samples were characterized by Zeta potential analyzer, SEM, TEM and FTIR etc. The results showed that the optimal conditions for coating were as follows: the mass concentration of titanium dioxide being 10%, the dosage of aluminum sulfate 4%, the temperature 60℃ and the stirring rate 290 r/min. The primary factor influencing the coating was the concentration of titanium dioxide, and that a low concentration was better for the coating of the surface of the rutile titanium dioxide. Al2O3 was adsorbed on the surface of the rutile titanium dioxide in the form of covalent bond and Al-O-Ti bond formed.