A stereoscopic image synthesis method includes the following: receiving a first image corresponding to a first view angle and a second image corresponding to a second view angle; obtaining a disparity map corresponding to the first image and the second image; determining a zero disparity region according to the disparity map; adjusting the disparity map according to the zero disparity region to obtain a shifted disparity map; linearly or non-linearly adjusting the shifted disparity map according to the shifted disparity map and a preset maximum range to obtain an adjusted disparity map; generating a plurality of virtual view angle images according to the adjusted disparity map, the first image, and the second image; and enhancing a two-dimensional depth cue of the virtual view angle images according to the adjusted disparity map.