Light-homogenizing devices, as key components in optical systems, directly influence the overall performance of these systems. With the continuous advancement of science and technology, research and development of light-homogenizing devices have garnered increasing attention. Among various light-homogenizing technologies, Holographic-polymer Dispersed Liquid Crystal (H-PDLC) volume gratings have shown significant potential in display technology and lighting systems due to their unique advantages, such as thinness, low-cost fabrication, and light tunability, offering superior solutions for the design of light-homogenizing display devices. These characteristics of H-PDLC gratings make them highly applicable in fields like display technology and lighting systems. However, to achieve H-PDLC gratings with high diffraction efficiency and transmittance, in-depth research is required on the selection of holographic materials, the phase separation of polymeric liquid crystals, and the grating morphology. Researchers worldwide have made certain achievements in these areas, but the application and development of two-dimensional H-PDLC gratings still face challenges, particularly in terms of diffraction efficiency and structural stability. To address these issues, this study derived a three-wave interference holographic theory and designed a corresponding three-wave interference holographic optical path. Utilizing COMSOL Multiphysics software, a refractive index model corresponding to a one-dimensional grating formed by three-wave interference was constructed, thereby validating the feasibility of using the three-wave interference holographic optical path to prepare one-dimensional gratings. In the experiments, by precisely controlling the angle of the reflecting mirrors in the exposure optical path, the exposure angle between the beams was managed, leading to the successful fabrication of H-PDLC one-dimensional gratings with three distinct grating periods, corresponding to diffraction angles of 10.4°, 14° and 18.4°, with an angle error kept within ±0.5°. In terms of fabrication technology, this study successfully prepared H-PDLC gratings on Tri-cellulose Acetate (TAC) membranes and created a two-dimensional grating film with two mutually perpendicular one-dimensional gratings through a superposition method. The advantage of this method is that the two independently formed grating morphologies are more stable during the interference process, effectively avoiding diffusion-related defects that might occur during the fabrication process. To produce gratings over a larger area, the study further explored the relationship between exposure power and grating diffraction efficiency. Results indicated that as the exposure power decreased, so did the diffraction efficiency of the grating. This phenomenon is attributed to the reduced energy absorbed by the photoinitiator, leading to slower monomer polymerization rate and liquid crystal diffusion rate, which in turn fails to form a well-defined phase-separated structure in the holographic grating. Based on these findings, the study optimized monomer materials by comparing the one-dimensional grating diffraction efficiency under low-power exposure conditions for two types of acrylate monomer systems: PDDA (polymerizable oligomer with acrylate groups) and TMPTA (trimethylolpropane triacrylate). The results showe that under the same exposure conditions, the TMPTA system achieves a first-order diffraction efficiency of 40.43%, while the PDDA system reaches 63.33%, significantly outperforming the TMPTA system. This is believed to be due to the higher molecular weight of PDDA, which allows for the formation of a more compact and stable polymer chain structure during polymerization, resulting in a higher quality polymer network that enhances the diffraction efficiency of the grating. To further enhance the grating's diffraction efficiency, the study optimized the ratio of monomer PDDA to film-forming resin EP828. SEM inspections were conducted to observe the surface morphology of the gratings under different material ratios. The results indicate that increasing the PDDA content appropriately improves the phase separation within the grating structure, thereby enhancing the diffraction efficiency. When the ratio of PDDA to EP828 was adjusted to 2∶1, with an exposure power of 5 mW/cm2, the H-PDLC grating achieved a first-order diffraction efficiency of over 90%. The final two-dimensional grating film had dimensions of 50 mm×50 mm, with a transmittance exceeding 90% across the visible light spectrum. This achievement not only provides a new theoretical approach to the design of H-PDLC gratings but also experimentally verifies their high performance, laying a solid foundation for further research and application of H-PDLC gratings. In summary, this research successfully addresses the challenges related to diffraction efficiency and structural stability of H-PDLC gratings through rigorous theoretical analysis and experimental validation. By optimizing the material composition and exposure parameters, this study significantly improves the diffraction efficiency and light homogeneity of H-PDLC gratings, which is of great significance for promoting their application in display technology and lighting systems. Future research can further explore various material combinations and fabrication processes to achieve H-PDLC gratings with even higher performance, meeting the growing demands of optical systems.