Using Aluminum nitrate, TEOS and zirconium oxychloride as precursor, Al2O3-SiO2-ZrO2 composite membranes were prepared by sol-gel process. Influence of sol composition and sintering process on the quality of the Al2O3-SiO2-ZrO2 composite membranes were studied. Stability of sol, thermal stability, crystalline phases and surface morphology of Al2O3-SiO2-ZrO2 composite membranes were analyzed by viscosity test, thermogravimetric(TG-DTG), X-ray diffraction(XRD) and atomic force microscope (AFM). The results show that the prepared sol is transparent and stable and it has moderate viscosity when Al2O3-SiO2-ZrO2 (mol / mol / mol) = 1:2:0.5. Calcines the dried gel at a speed of 0.5 ºC/min from room temperature to 600℃ for 2h, meanwhile heats up slowly at a speed of 0.25 ºC/min and insulates a few minutes on 75ºC and 240 ºC. Like this, Al2O3-SiO2-ZrO2 membranes of transparent, stable, smooth surface, good compactness and no cracking can be obtained.