Abstract: Stray currents follow multi-source characteristics and can be divided into direct current, alternating current and ground current. They are subject to a large corrosion strength concentrated in a local position. There are two causes for stray currents, namely current leakage and potential gradient. Direct stray current corrosion is essentially electrolytic action of electrochemical corrosion, while corrosion mechanism of alternating stray current needs further studies. Current protection means adopted include avoidance of stray current interference source, increase of grounding resistance, electric drainage protection method, electrochemical protection method, material surface modification and enhancement of daily maintenance. Finite element method and boundary element method are mainly used for numerical calculations of stray current corrosion, of which the boundary element method is applied more widely. Field potential observation method is mainly used to determine a stray current corrosion protection program while it will become a future development trend to determine the optimum protection program by the combination of numerical calculations and model experiments. In the case of uneven soil media, blocked boundary element method can be used to improve calculation accuracy.