Tetrahedralization of 3D models is an important technique in finite element mesh generation. An algorithm of tetrahedral mesh generation and optimization is proposed in this paper. It first uses principal component analysis of 3D models for the preprocessing. Then the initial tetrahedral mesh is built based on the body-centered cubic while the movement of cutting point is improved via Laplacian coordinates for keeping local features. Finally, it optimizes the quality of the tetrahedral mesh by using the function of energy-density error. Experimental results demonstrate that this method is viable, effective, and can preserve the model feature well.