Abstract: In order to achieve the goal of saving material and lowering the cost, a scheme is proposed to quickly build and optimize improved skin-truss structure, which minimizes the volume of the printing objects under constrained conditions including physical and mechanical properties, force balance, self-balance, and printability. A mesh simplification strategy is utilized to rapidly build exterior truss structure, which maintains topology similarity of the original mesh to avoid conflicts between truss and skin. A method based on experimental analysis is put forward to construct interior truss structure without interior nodes, which not only can significantly shorten the overall optimization time, but also achieves better results in saving material under mechanical constraints, combining mechanics criteria method and particle swarm optimization algorithm, utilizing full stress method to calculate the strut radius of the truss structure, and considering them as initial value of the optimization algorithm, improving the capacity and efficiency of the algorithm in the search for globally optimal solutions, and realizing to optimize the cross-sectional dimensions and the topological structure of truss structure simultaneously. The test results show that the method described above is robust, efficient and cost-effective.