Abstract: It is very important to calculate the corrosion effects of HVDC grounding current on the pipelines accurately and take proper protective measures for the energy transmission safety. Related prediction methods are still short of systematic research considering the nonlinear polarization between on the interface between soil and the interfered pipeline. A mathematical model was established for the coupling voltage and current on the buried oil gas pipelines induced by grounding currents considering nonlinear polarization. A method was proposed to calculate three- dimension electric flow field by combination of the method of moments (MoM) and the finite element method (FEM) when considering nonlinear polarization. The validity of calculation method was verified by experiments. Error analysis results were obtained by comparing the calculation results of no polarization model, linear polarization model and nonlinear polarization model with the experiment results. The calculation results of a typical engineering cases were analyzed in the end. The results show that the proposed method can effectively consider the influence of nonlinear polarization. Pipeline corrosion risk will be overestimated or underestimated when assessing the pipeline safety considering no polarization or linear polarization. The nonlinear polarization between pipeline meatal and soil cannot be neglected for accurate prediction of the leakage current density and pipe-to-soil potential. A lot Science and Technology Project of State Grid Corporation of China (GYB17201600172). unnecessary protection and maintain cost can be avoided, alone with the risk resulting from underestimated prediction in design and construction stage by proper calculation and analysis when considering nonlinear polarization.