In this study, the silica-based organic-inorganic hybrid nanocomposites have been developed for applications as the hard coating on the PET substrate surface. The inorganic material was functional polysiloxane with polyheral oligomeric silsesquioxanes (POSS)-like nanostructures, prepared by sol-gel method using 3-(Methacryloyloxy)-propyltrimethoxysilane (MAPTMS) in the presence of an acidic catalyst. The polymer matrix used was the UV-curing polyurethane acrylate resin. The surface functional groups and the sizes of nanoparticles were controlled to ensure strong interaction between the nanoparticles and the polymer matrix, resulting in high transparency and abrasion-resistant nanocomposite coatings, as the organic-inorganic nanocomposite coatings exhibit great performance in hardness and visible light transmittance on the PET substrate. With good optical, mechanical and physical performance, the multifunctional transparent nanocomposite coatings are suitable for the applications in automotive, optoelectronics and electronics industries, etc.