Abstract: Aiming at the problem of the huge terrain data and low frame rate in large-scale terrain rendering, this paper proposes a LOD algorithm based on Enclosing Ball Screen Error of Quad-tree. It divides many blocks and indexes data blocking for terrain data, implementing the local loading of terrain data. In the preprocessing phase, the algorithm builds the enclosing ball for every terrain block to reduce the data storage and computation in real-time rendering stage. In real-time rendering stage, it establishes LOD model based on enclosing ball and implements the real-time rendering for large-scale terrain, according to the viewing frustum culling based on projection and bounding sphere to loading terrain blocks, combined with the data structure of quad-tree to build bounding spheres. Experiments results show that the method can improve the frame rate to ensure smooth large-scale terrain rendering and the performance of real-time.