The method of sol-gel co-assembling high quality, large area silica inverse opal films is studied. Hydrolyzed sol-gel precursor solution is added in monodisperse polystyrene (PS) colloidal solution to co-assemble composite colloidal crystal film which is infiltrated with silicate gel simultaneously. PS colloidal crystal template is removed by calcining the composite colloidal crystal film to obtain the silica inverse opal film. Silica inverse opal films of different pore sizes are fabricated by this method after researching the ratio of added hydrolyzed sol-gel precursor solution, the temperature of vertical evaporation, and the sinter temperature. The structures and the elements of fabricated silica inverse opal films are characterized by scanning electron microscope and X-ray energy spectrometer, and their optical transmission spectra are measured. Research results indicate that silica inverse opal films fabricated by sol-gel co-assembly method are highly ordered in large area, and the pore sizes are controllable in a wide range; measured transmission spectra show an evident band-gap, whose central wavelength is coincident with calculated result.