Abstract: To obtain the concept design of the truck frame structure, the efficient computer aided design method to optimize the structure of the truck frame is provided based on independent continuous mapping method. And the transformation of the local stress constraints of element into the global stain energy constraints of structure is achieved by virtue of the strategy of globalization of stress constraints. The optimal topology model of the truck frame structure subjected to the structural weight is established with stress constraints. The problem about topological optimization of continuum structure with multi degree freedom under stress constraints is studied. In addition, the dual model corresponding to the optimal model of continuum structure is solved by the serial quadratic programming. Furthermore, the numerical analysis about the truck frame structure shows that the method is effective and efficient.