Polystyrene-based nano-dielectric is a composite material formed by polystyrene as the matrix, and inorganic Nano fillers are uniformly mixed in the polystyrene matrix. Because nanoparticles have quantum effects, size effects and interface effects, so that composite materials have more excellent performance, so polystyrene-based Nano-dielectrics have received extensive attention in the field of high-voltage DC cables. In this article, the image structure of LiNbO3 ferroelectric domains is observed by using electrostatic polystyrene nanoparticles based on digital imaging technology. The article first introduces the advantages of ferroelectric memory, based on this, a series of research and exploration are launched, and then the analysis index method of digital image technology is proposed, and the flow chart of related texture feature processing is given. Then, based on the digital imaging technology, the dielectric properties of the polystyrene nanocomposite were studied, and a set of experiments were designed to observe the lithium niobate ferroelectric domain structure based on the digital imaging technology. Experimental results show that periodic dislocations are an important cause of the failure of ferroelectric thin films, and observation of the domain structure of lithium niobate ferroelectrics based on digital image technology can improve its clarity by 85%.