AbstractDC stray current has a great influence on the corrosion of buried pipelines. In this article, first, we deduce the equation of DC stray current interference on pipeline and determine the corresponding boundary conditions. Second, we discretize the mathematical model with boundary element method. Third, the numerical simulation software BEASY is applied to study the interference corrosion of cathodic protection system. Five types of cathodic protection (CP) interference are considered, namely, anodic, cathodic, combined, induced, and joint interference. Moreover, the effects of different parameters on the degree of the CP interference are investigated. The results show that the degree of interference will decrease with the increase of soil conductivity; smaller coating damage rate will make interference more concentrated; anode parameters have a significant impact on anodic interference but have almost no effect on cathodic interference; for combined, induced, and joint interference, the likelihood for corrosion occurrence will be high at the current outflow point on pipeline.