A structural bionic design process is systematically presented for lightweight mechanical structures.By mimicking biological excellent structural principles,the stiffening ribs of a machining table and a moving column were redesigned for better load-bearing efficiency.Finite element method(FEM) simulation and model experiments were carried out for performance verification,which showed the increase of structural static and dynamic performance.Structural bionic offers a new solution to change conventional structures for high specific stiffness. A structural bionic design process is systematically presented for lightweight mechanical structures. By mimicking biological excellent structural principles, the stiffening ribs of a machining table and a moving column were redesigned for better load-bearing efficiency. Finite element method (FEM) simulation and model experiments were carried out for performance verification, which showed the increase of structural static and dynamic performance. Structural bionic offers a new solution to change conventional structures for high specific stiffness.