Polyvinyl alcohol/acrylamide based photopolymer system has a relatively low spatial resolution, which limits its wide applications in the fields such as reflection display holography, high-density holographic data storage, etc. A new strategy of employing low molecular-weight polyvinyl alcohol as binder to improve the spatial resolution of such photosensitive system is proposed. The comparative experiments of different photosensitive system with various molecular weights (72000,15000,9000) are conducted to study their effects on the diffraction efficiency and spatial resolution. The experimental results show that the photosensitive system with low molecular weight of 9000 has much higher resolution and diffraction efficiency, and bright volume transmission grating with spatial frequency of 3000 line/mm and diffraction efficiency higher than 85% can be recorded successfully on the optimum photopolymer material at the exposure level of 40 mJ/cm2. Finally, the preliminary applications of angular multiplexing holographic storage are successfully demonstrated.