Abstract: In consideration of the structural characteristics of high-grade steel pipes and the great influence of weld failure on the safety of pipelines, the bearing capacity of girth welds of pipelines has become a research hotspot in the pipeline industry. The full-automatic joint in the China–Russia Eastern Gas Pipeline was taken as the research object, and the differences of material constitutive relations in the four zones of root welding, heat affected zone, base metal and fill welding in girth welding joint were accurately considered. The numerical simulation model based on finite element method was established for analyzing the strain capacity of pipeline girth welding joints. Quantitative analysis was made on the influence of the matching ratio of toughness and other factors on the driving force of crack growth in pipeline girth welds under combined operating conditions of base metal yield ratio, operating internal pressure and load type. The failure determination method of static crack initiation was adopted. The apparent fracture toughness value was taken as the critical criterion. In combination with the actual variation range of the material characteristic parameters of pipes and girth welding joints of the China–Russia Eastern Gas Pipeline, the strain capacity of the China–Russia Eastern Gas Pipeline girth welding joints under the most unfavorable conditions within the design operating conditions was calculated. The results show that improving the strength matching of weld zone is conducive to reduce the driving force of crack growth in the joint effectively. Increasing the internal pressure of the pipeline or raising the yield ratio of the base metal will cause the driving force of crack growth larger under the same strength matching condition, and the driving force of crack growth under tensile load is greater than that under bending load. This method can be used not only to guide the determination of welding parameters according to the performance requirements of welded joints, but also for the applicability assessment of defective welded joints in service pipelines.