In view of the slow loading speed of cable 3D visualization scene, a simplified algorithm for extracting the outer surface of 3D model and a multi-level of detail R-tree index data scheduling organization method are proposed. Firstly, the LOD level simplification of cable well and pipe trench models occupying a large amount of memory in three-dimensional scene is carried out, and the experimental results show that the amount of data is greatly reduced. Then, the simplified data is organized and scheduled according to the R-tree index structure of multi-level of detail. Compared with the traditional R-tree, the R-tree constructed by this method constructs a better tree shape in node selection and node splitting, which makes the data in progress. In the process of indexing and scheduling, it can improve the loading speed of 3D scene of cable engineering, and effectively realize the smooth display of 3D model in cable engineering.