The equivalent refractive index of porous silicon(PS)/polymer composite film for TE polarization was studied by two-dimension model of cylindrical pore.The relationship between the equivalent refractive index of PS/PMMA and porosity of PS or volume fraction of polymer impregnated in PS was given.In experiments,the equivalent refractive index of PS film (porosity=73%) impregnated polymer PMMA with different volume fraction for TE and TM polarization in 633 nm wavelength were measured respectively by m-line method.The theoretical results were consistent with experimental results.