Abstract: To satisfy the requirement of finite element analysis,an adaptive mesh generation technique based on ball-packing method for STL models is proposed.First the method recognized the curvatures of edges,curvatures of surfaces and area shape features of STL models,and then a size field was built by an octree,finally adaptive mesh was generated in STL surface based on ball-packing method.This method can generate a good conforming size-adaptive mesh efficiently without complex calculation of projection of nodes and intersection of fronts.The testing results show that this method is faster than NetGen and the quality of the meshes generated by this method is better than those produced by NetGen.