本文提出了桁架结构在多种荷载工况多种约束类型约束（位移、应力和尺寸约来）条件下最轻重量设计的齿行法．利用射线步把设计点拉到最严约束界面上，然后使用单位移准则步或满应力准则步来确定设计变量修改的方向和步长，直到找到一个满意的最优解为止。另外．本文还提出了修正的摄动法和敏度分析的降维法，应用这些方法于结构优化设计收到相当显著的效果．数字例题表明，这些近似的重分析方法在结构优化设计中是很有效的。 本文的方法可以用于由膜单元组成的多种单元组合结构。 In this paper, the truss structure method is proposed for the lightest weight design under various constraint conditions (displacement, stress, and dimensions). Use ray steps to pull the design point to the tightest constrained interface, then use the unit shift guideline or full stress guideline step to determine the direction and step length of the design variable modification until a satisfactory optimal solution is found. In addition. This paper also proposes a modified perturbation method and sensitivity analysis for dimensionality reduction methods. Applying these methods to the structural optimization design receives quite significant results. The numerical example shows that these approximate reanalysis methods are very effective in structural optimization design. The method herein can be used for a variety of unitary composite structures composed of membrane units.