Abstract: The lamppost design of the traditional computing method gives the unified pole height, wall thickness and arm length, which leads to problems as follows: steel waste is serious for the bigger design margin; lamppost cracks without enough safety reserves. Based on theory of structural mechanics, the lamppost design variables and optimized objective function were set up, the optimal mathematical model was established. By taking a typical 10 m lamppost in Ma'anshan city main road as the research object, the nonlinear programming method was used to optimize calculation of design variables, such as wall thickness, diameter and the arm length. The calculation results show that the safety factor is about 2.43, the design of lamppost has enough safety reserve and greater optimization space; the safety factor deceases gradually with the increase of the arm length and the decrease of the wall thickness. It is more economic and reasonable for lamppost that the safety factor is 2.0, the wall thickness is 3.66 mm, and the arm length is 4.0 m in Ma'anshan city main road.