Abstract: An algorithm for rapid slicing of STL model based on sorting by triangle adjacency in layers is proposed,which establishes adjacency relationship between triangle meshes by adopting method of adjacency insertion.The slicing planes intersecting with the triangle meshes are determined by slicing precision associated with minimum and maximum values of projection of each vertex of triangles on normal direction of the slicing plane.Through comparing the relationships between the common edge of two adjacent triangle meshes and the slicing plane,intersection link lists are established.In contrast to existing algorithms based on complete topological information reconstruction and grouping sort,this algorithm does not require complete topological information and grouping sort but records the adjacency relationship of triangle meshes into intersection link list in order to save system resources and increase slicing efficiency.The feasibility and efficiency of this algorithm is validated by testing on a STL model of piston.