Abstract: An numerical model is created to calculate extreme pressure of internal corroded pipeline, which is based on finite element software and adopts the model of exponential kinematic material, the method of defect dissected by orthogonal areas and entire model meshed with hexahedron. On the basis of criterion B31G, it gives a more accurate fitting formula which can provide a more reliable reference to analyze the extreme pressure of corroded pipeline. A calculation case is given and identified.