The multi-resolution terrain technique is the most efficient tool for real-time rendering of a complex terrain. In this paper a bintree-based optimized algorithm for level of detail (LOD) terrain is applied based on the overall research of former algorithms. At the same time, the node evaluation function is given according to the influence of viewer?s orientation and terrain?s roughness and deviation, which gives an accurate explanation of the LOD node and increases the executive efficiency. Meanwhile the method of recovering cracks which Duchaineau used in his whitepaper is improved. Next, this paper presents an approach to maintain the frame coherence. Last, we use the improved algorithm to simulate the terrain and get a good effect.