Holographic-polymer dispersed liquid crystal (H-PDLC) volume holographic gratings provide a better approach for holographic waveguide couplers due to stable chemical state, simple fabrication and low cost advantages. This article proposes the development of H-PDLC transmissive volume gratings using composite acrylic high/low refractive index matching modulation. Firstly, the formation mechanism of H-PDLC grating was introduced based on the combination of coupled wave theory and molecular diffusion theory. Then, grating materials with different functional monomers were screened through experiments, and holographic diffraction properties were studied. On this basis, the performance of high-frequency volume holographic H-PDLC gratings was further optimized by increasing the content of initiators. The experimental results show that the H-PDLC formulation of this dual monomer can achieve a visible light transmittance of over 90%, with a diffraction efficiency of 90% and a response bandwidth of 99 nm at 973 lp/mm; At 2 941 lp/mm, the diffraction efficiency is 75.4% and the response bandwidth is 29 nm. The H-PDLC grating has considerable application prospects as a coupler in waveguide display systems.