3D technology has been widely used in the fields of architecture, medical image, cultural relic protection, filmproduction and 3D game. The polygon mesh is the most commonly used method for expressing the 3D model, itconnects the points on the surface of the 3D model into polygons as a unit, which can express complex surfaces andprovide strong adaptability. Especially in the use of triangular mesh the most widely used. But the triangular griddisplay, simplifi ed, progressive transmission algorithm is not suitable for large-scale data sets. The triangular mesh datafi le described in this paper with the boundary ball data fi le conversion system will represent and gradually compressthese triangular meshes. This representation is not only compact, but also can be quickly calculated, its biggest featureis the high compression ratio, saving a lot of time and space, which makes it suitable for large-scale data sets. Itsexecution program can serve large-scale 3D data processing projects. This article has demonstrated that this system canbe converted to include a large order of magnitude polygon model.