ASME B31G is the international criteria to assess the failure stress of corroded pipeline, taking into account its conservatism, this paper studies the failure stress of corroded pipeline based on the modified B31G, and considers some random variables that contains pipeline wall thickness, corrosion rate, operating pressure, defect depth and so on, so a limit state function of corroded carrying Oil/Gas is established. Afterwards, the first order and second moment method is employed for research on the reliability of corroded pipeline, and calculation on reliability index, failure probability and remaining life. In addition, to further standardize the management of corrosion of pipelines, taking into account the relevant provisions of American Petroleum Institute, different failure probability of pipeline were graded. In the final, a sensitivity analysis was carried out on random variables involved in the problem. The results of sensitivity analysis indicate that the failure probability is the most sensitive to the coefficient of variation of wall thickness.