This paper addresses the issue of image quality degradation in reconstructed holograms under noisy conditions through computational holography. By establishing a dual-metric evaluation system based on peak signal-to-noise ratio (PSNR) and structural similarity index measure(SSIM), we systematically investigate the influence of noise on the reconstruction quality of four typical types of computer-generated holograms. Based on MATLAB simulation platform, a comparative analysis is conducted on the performance of detour-phase holograms (Lohmann type Ⅲ), modified off-axis reference beam encoding (Burch’s and Lee’s encoding), kinoforms, and computer-generated holographic interferograms under different noise coefficients. The results indicate a clear correlation between the noise coefficient and the quality of reconstructed image, the PSNR values decrease with increasing noise levels, with a more pronounced decline observed in the low-noise range (ef1≤0.3). Moreover, the SSIM metric demonstrates greater overall stability, particularly excelling in modified off-axis reference beam encoding methods. Optimization of encoding strategies effectively enhances noise resistance—for instance, Lee’s encoding maintains a PSNR of approximately 19 dB at ef1=1.0 through orthogonal component decomposition and multi-level grayscale quantization, while Lohmann type Ⅲ encoding achieves a 94.2% improvement in PSNR by increasing the aperture width. Although continuous-tone holograms outperform binary holograms in detail retention, binary methods remain practically valuable in specific application scenarios. This study provides a theoretical basis for selecting computer-generated hologram (CGH) encoding schemes under various noise environments.