为改善超高压法兰双头螺柱在紧固的过程中各螺柱会因弹性相互作用影响而发生预紧力松弛和分布不均的问题，最终影响法兰连接的密封性。通过现有的文献建立了弹性相互作用矩阵，并采用有限元分析方法对紧固顺序、紧固轴数、紧固轮次不同紧固工艺下的螺柱预紧力分布进行了研究，基于此对比分析了不同紧固工艺的优缺点及适用性，最终采用弹性相互作用系数法（elastic interaction coefficient method, EICM）对螺柱初始预紧力优化。结果表明：单轴紧固模式中的星形模式和多轴紧固模式中的四轴圆形模式紧固效果最好，紧固后的各螺柱预紧力更接近于目标预紧力，同时所需载荷步较少；其次，增加紧固轮次可使紧固后各螺柱接近于目标预紧力，离散度更小；此外，采用基于EICM优化后的螺柱初始预紧力进行紧固后，得到的螺柱最终预紧力分布较优化前得到明显的改善。可见研究结果可为超高压法兰双头螺柱的紧固提供理论指导和技术支持。

In order to improve the problem of preload relaxation and uneven distribution of double-headed studs during the tightening process of ultra-high pressure flange double-headed studs, which ultimately affects the sealing properties of flange connections. An elastic interaction matrix was established through existing literature, and finite element analysis method was used to study the preload distribution of studs under different fastening processes in the fastening sequence, number of fastening shafts, and fastening wheels. Based on this, the advantages, disadvantages, and applicability of different fastening processes were compared and analyzed. Finally, the elastic interaction coefficient method (EICM) was used to optimize the initial pre tightening force of the bolts. The results show that the star mode in the single-axis fastening mode and the four-axis circular mode in the multi-axis fastening mode are the best, and the preloading force of each stud after tightening is closer to the target preloading force. At the same time, fewer load steps are required. Secondly, increasing the fastening wheel can effectively make each stud close to the target preload force after tightening, and the discreteness is smaller. In addition, the initial preload force of the stud optimized based on EICM is adopted after tightening, the final preload distribution of the obtained stud was significantly improved before optimization. It is concluded that the research results can provide theoretical guidance and technical support for the fastening of ultra-high pressure flange double-head studs.