The Al2O3 ceramic filter membrane is easily clogging by dye macromolecules during the process of filtering dye wastewater, resulting in a decrease in the water flux of the Al2O3 ceramic filter membrane. Ti(OH)4-AlOOH composite sol was prepared by the sol-gel method with butyl titanate and aluminum isopropoxide as precursors, and TiO2-Al2O3 composite powder was obtained by heating at a temperature of 450 ℃. The influence of the molar ratio of Ti（OH）4 and AlOOH on the particle size distribution of composite sols and the photocatalytic performance of TiO2-Al2O3 composite powders was characterized by using SEM, nanoparticle size/potential meter. The results show that when the molar ratio of Ti（OH）4 and AlOOH is between 0 and 0.4, the average particle size of the colloidal particles decreases from 67.5 nm to 34.0 nm with the increase of the molar ratio of Ti（OH）4 and AlOOH, and the Zeta potential of the Ti(OH)4-AlOOH composite sol increases from 43 mV to 53 mV. When the molar ratio of Ti（OH）4 and AlOOH is 0.4, the removal rate of crystal violet by composite powder up to 79.3%, and the reaction rate constant increases to 0.018 min-1. The ceramic membrane prepared by TiO2-Al2O3composite powder can effectively degrade the macromolecules deposited on the surface, and solve the problem of clogging of the ceramic membrane.