This research presented the preparation of multilayer films on poly(ethylene terephalate) (PET) Substrate by electrostatic self-assembly technology. The silver nanoparticles were characterized by UV–vis spectrometry and scanning electron microscopy (SEM). The sequential dipping of hydrolyzed PET substrate in dilute solutions of poly(diallyldimethyl ammonium chloride)(PDDA) and silver nanoparticles to fabricate multilayer films. The multilayer films were monitored by UV–vis spectrometry, the surface plasmon resonance (SPR) obtained at 420 nm confirmed the existence of nanosilver on the PET film. The silver nanoparticles were also verified by the Inductively Coupled Plasma Spectrometry (ICP) and thermogravimetric analysis of the multilayer film. The transmission spectra indicated that the PET films contained silver nanoparticles have better UV protection property.