As the data volume of point clouds obtained by means of the laser line scanning mode is very large, and not convenient for storage, processing and analysis. A simplified expression of point cloud data based on vector angle computing as well as the corresponding STL file generation method is introduced. The proposed method can not only reduce point cloud data efficiently, but also reserve the integrity of the original data object information by retaining key inflection point data of the related object. Different from common generating method of the STL file, the gap and distortion between triangles are avoided by the STL file generation method based on adjacent points analysis and is of great applicability and practical reference value.