The 3D terrain visualization is one of the most important technologies of Synthetic Vision System (SVS).Considering that the airborne SVS has the characteristics of large-scale terrain scene, less computing resource and rigorous real-time requirement, we studied such critical technologies as scheduling of terrain blocks, levels of detail, and texture generating.Based on which, a 3D terrain visualization system suitable for SVS was designed and implemented.The experimental results showed that our terrain visualization system satisfies the requirement of SVS both in visual effect and real-time performance.