Abstract: Rendering performance optimization is needed to display dense 3D models in Cesium requires improving the. However, the native approaches are unstable and will cause bad rendering results. To avoid this problem as much as possible, a mechanism is proposed in this paper to enable high-performance rendering when the camera state changes in which the camera states change pauses primitives loading, and applies parameter settings and algorithms that can improve rendering performance but may cause bad rendering results. Besides, this paper proposes a heap-based 3D tile draws command limitation approach, which can directly limit the number of draw commands and reduce the amount of GPU computation. The results prove that the mechanism of high-performance rendering when camera state changes are feasible. The mechanism outperforms the max screen space error (MSSE) increasing and the draw commands limiting, which excels reducing the resolution scale (RS) in improving rendering performance. Limiting the draw commands can ensure the stability of rendering performance compared with increasing MSSE.