Metasurface holography based on planar optical devices has attracted considerable attention due to its potential for miniaturizing optical components and systems. However, traditional on-axis holography has inherent zeroth-order diffraction and twin-image effects, which significantly degrade image quality and limit its practical applications. Off-axis metasurface holography, in contrast, provides a promising solution to overcoming these limitations. In this work, we design a metasurface hologram composed of titanium dioxide (TiO₂) nanopillars on a silicon dioxide (SiO₂) substrate, by using the high refractive index and low optical loss of TiO₂ in the visible light range to achieve efficient phase control. The unit cell height is set to 600 nm to ensure sufficient phase accumulation, and the working wavelength is 635 nm. The hologram is constructed by mapping the continuous 0–2π phase distribution obtained from computational holography onto the unit cell array, and changing the nanopillar diameter to achieve full phase coverage. We systematically investigate the effect of the unit cell period on the imaging position in off-axis holography. Numerical simulations show that as the period increases from 280 nm to 350 nm, the center of the holographic image gradually shifts toward the center of the image plane. The optimal period is found to be 324 nm, at which the image is reconstructed precisely at the designed position. Further simulations using different off-axis angles (0°–45°) and nanopillar heights (600–2000 nm) confirm that the imaging position remains fixed at the target location, indicating that it is mainly determined by the unit cell period rather than other structural parameters. These results demonstrate that by carefully selecting the unit cell period, the holographic image can be accurately reconstructed at a predetermined positions with high image quality, providing theoretical guidance for designing high-precision off-axis metasurface holographic imaging systems.