As the service life of China's oil and gas pipelines increase, the pipelines are inevitably subjected to defects such as corrosion and denting due to external factors. It becomes imperative that the impact of these defects, including denting and corrosion, on the ultimate bearing capacity of the pipelines be analyzed. A simulation was conducted on the safety of an X80 pipeline with dents and corrosion defects. By changing factors such as dent length, width, depth, and material type, the influence of a single dent area under the action of spherical and ellipsoidal pressure heads on the ultimate bearing capacity of the pipeline was analyzed. At the same time, the influence of various factors such as the size and spacing of dents and dents on pipeline safety was studied when composite defects such as dents and corrosion coexist. The results show that the length of dents, corrosion length, and corrosion depth are important factors affecting the ultimate bearing capacity of composite defects, and the damage to pipelines is greater when dents act in the vicinity of the corrosion center point.