CATIA CAA对象扩展是自定义对象的主要途径，也是当前的开发难点。基于电阻焊工艺参数和约束条件分析，提出了以CAA用户界面设计、自定义对象、参数验证和实体创建为技术路线的焊点/缝建模框架，进一步针对螺母边焊的焊点直径计算、焊点中心至边线距离计算展开了参数自动计算和验证问题研究。通过CATIA CAA二次开发技术，实现了汽车座椅骨架电阻焊工艺中的平板凸焊和螺母焊的参数化建模，提高了汽车座椅骨架零部件焊点设计效率，并为多类型焊点（点焊、弧焊等）管理系统开发奠定了基础。
CATIA CAA object extension is the most important way of self-defined object creation and is also the difficulty of development. Based on analysis of processing parameters and restrains of resistance welding, a framework for welding spot modeling via the technical route of CAA user interface design, self-defined object, parameter validation and entity creation, is advanced. Furthermore, problems of parameter automatic computing and validation are studied through examples of spot diameter computation of nut side weld and distance computation between spot center and sideline. Finally, parametric modeling of plate projection weld and nut weld of resistance welding of resistance welding for vehicle seat framework (VSF) is realized by CATIA CAA redevelopment, which improves weld design efficiency of VSF parts and provides fundamental for multi-type welding (including spot welding, arc welding, etc.) management system development.