In present work, nanocomposites films of polyethylene oxide (PEO), copper oxide (CuO) nanoparticles and indium oxide (In₂O₃) nanoparticles have been fabricated for discoloration and photo-degradation of dyes pollutants with high efficiency, few cost, anti-aggregation and high dispersion of nanoparticles. The structural and optical properties of PEO/CuO–In₂O₃ nanocomposites have been investigated. The structural properties were included the tests: optical microscopic (OM), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The optical properties of PEO/CuO–In₂O₃ nanocomposites were studied in wavelength range (200–800) nm. The results of optical properties of PEO/CuO–In₂O₃ nanocomposites showed the absorbance of PEO increases about 57.4% at (λ = 500 nm) and the energy gap of PEO reduces about 41.1% with adding of CuO–In₂O₃NPs which may be considered as a key for various optical and electronic fields. The optical constant of PEO were improved by adding of CuO NPs and CuO–In₂O₃ NPs. The PEO/CuO–In₂O₃ nanocomposites have been utilized for photo-degradation of dyes pollutants. The results showed prepared nanocomposites can be used for excellent photo-degradation of dyes with high efficiency reached 91% and low concentration of nanoparticles.