Abstract <p>With the acceleration of urban construction in China, subway lines across waters (rivers, lakes and oceans) have been built by many water-containing cities to meet the development needs. This paper is targeted at this issue, and relevant literature is comprehensively analyzed, and the current situation of cross-water subway construction is arranged, and it is found that there are many complex technical problems in such subway lines, among which the stray current problem is the key. Due to the special environment, the stray current distribution and corrosion characteristics of cross-water subway lines are significantly affected. Firstly, the distribution law of stray current in cross-water environment is deeply explored. Secondly, the corrosion characteristics of stray current in cross-water environment are studied. Finally, the harm and protection measures of stray current to buried pipelines in cross-water subway lines are introduced, and a theoretical reference is provided for the safe operation and maintenance of cross-water subway system.</p>