Abstract: To predict the ultimate internal pressure of subsea pipelines in case of medium/high-strength steel corrosion, a plastic finite element analysis is made. Besides, considering the nonlinearity and geometric nonlinearity of materials, the nonlinear analysis model is built and the modeling results are compared with the experimental data to verify if the finite element model is reasonable and accurate. On this basis, the impacts of corrosion depth, length and width on ultimate internal pressure are obtained. The formula for ultimate load of pipelines with axial corrosion is also gained by regression. Compared with the burst test data of corrosion pipes and existing corrosion calculation methods, it is proved that this method can provide more accurate results, which will be used as a basis for assessing subsea corrosion pipelines under internal pressure loads.