An optimization scheme based on wide-activated deep residual network super-resolution (WDSR) is proposed for the stereoscopic image synthesis algorithm of a cylindrical grating display. Unlike the traditional synthesis scheme, the WDSR algorithm is used to replace, partially or fully, the interpolation algorithm to reduce the antialiasing effect of the image. Thereafter, the viewpoint mapping process is accelerated based on the subpixel mapping table by making masks. Subsequently, a stereoscopic image with a better quality is obtained. The experimental results demonstrate that the proposed scheme can improve the signal-to-noise ratio and quality of the stereoscopic composite image when the same subviewpoint image is used for verification.