Currently in China X80 pipeline laying mostly concentrated in mountainous areas, oil and gas pipeline transmission distance, through the complex and diverse terrain, the pipeline by the buried environment will not only appear corrosion defects, but also by the impact of soil slippage to reduce the pressure-bearing capacity of the pipeline, resulting in pipeline perforation, broken, leading to oil and gas leakage accidents, further leading to fire, explosion and environmental pollution and other major safety accidents. In view of the important strategic position of oil and gas pipelines and the severity of accident hazards, it is important to study the ultimate bearing capacity of buried corroded pipelines. With this purpose, this paper analyzes the existing pipe-soil coupling theories based on the large-scale test in the field, optimizes the nonlinear contact model, and establishes a nonlinear corroded pipe-soil interaction model and verifies its accuracy. By using the existing soil load application function and coupling the actual soil slip data, the inhomogeneous movement of soil slip is realized. Based on the existing corrosion size characterization methods, the effect of corrosion size on the ultimate load carrying capacity of intact pipes was further verified by means of a combination of FEA and experiments. Specifically, the effects of soil slip under no load and internal pressure coupled conditions on the mechanical behavior of corroded pipelines are compared and analyzed; the necessity of considering soil slip is clarified; the influencing factors such as pipe corrosion size, operating internal pressure, and corrosion position are analyzed to reveal the failure mechanism of buried corroded pipelines in mountainous areas. By using the pipe displacement at the strain failure as the evaluation index, and using the dimensional analysis method to reveal the relationship between each influencing factor and the ultimate load, the ultimate load prediction formula for corroded pipelines under soil slip actions is derived. The research results can help evaluate the safety condition of existing operating pipelines, release early warning for the structure safety of pipelines, and provide guidance for the safety protection of pipelines in mountainous areas.