本文采用问题归约方法的思想，认为图论割集算法和ＡＮＤ／ＯＲ图ＡＯ搜索算法是装配顺序生成理想的通用算法。但是，制约其实用化的关键问题是产品建模、约束类型的确定和各类型约束的求解。这方面与具体应用领域有关，必须具有开放式结构。同时，任何约束都不能仅仅认为是绝对约束和绝对不约束这两种情况，而应对约束附加约束程度系数。本文就此提出了构造焊接结构扩展关系图（ＥＲＧ）的建模方法和影响焊接结构生产工艺过程设计的七种约束类型及其约束程度系数求解方法。 In this paper, the idea of ​​problem reduction method is adopted, and it is considered that graph theory cut set algorithm and AND / OR graph AO search algorithm are ideal general algorithms for assembly sequence generation. However, the key problems restricting their practical application are product modeling, determination of types of constraints and solutions of various types of constraints. This area is related to the specific application area and must have an open structure. At the same time, any constraint can not be considered as both an absolute constraint and an absolute constraint, but rather as an additional constraining factor. In this paper, a modeling method of constructing welding structure expansion diagram (ERG) and seven kinds of constraint types affecting the design of welding structure production process are proposed.