A new method called vectorized structure approach is proposed for truss topology optimization, which effectively increases or reduces the structure elements by iteratively adding or removing nodes and bars. The approach was developed on structural vectorization using nodes’ coordinates. The mapping relationship between structural vectors and realistic structures is established by the geometry composition analysis rules. Therefore, the approach can generate the optimal solution contains the given set of required nodes. Two kinds of topology optimization methods are considered. The first method sorts vector elements in every mapping process and the second method just consider sorting elements itself to be part of optimizing process. The numerical experiments have shown that both methods are effective.