The　coupling　effect　of　stray　AC　(alternating　current)+DC　(direct　current)　and　tensile　stress-induced　X70　pipeline　corrosion　is　complicated　with　its　mechanism　uncovered.　In　this　work,　the　corrosion　behavior　of　X70　pipeline　steel　under　three　different　corrosion　(including　an　individual　AC　corrosion,　mixed　AC+　150MPa　tensile　stress　corrosion,　coupling　effect　of　AC+　a　30A/m(2)　DC　interference　and　150MPa　tensile　stress　corrosion)　conditions　in　Dagang　soil　simulated　solution　was　investigated　by　COMSOL　Multiphysics　software　simulation,　electrochemical　tests,　scanning　electron　microscope　and　other　techniques.　The　results　indicated　that　with　the　increase　in　AC　density,　the　open-circuit　potential　of　the　X70　steel　samples　was　negatively　shifted　and　corrosion　rate　increased　in　three　different　corrosion　conditions.　The　corrosion　rates　of　X70　steel　samples　under　individual　AC　interference　were　almost　unchanged　when　150.9MPa　tensile　stress　was　applied.　When　applying　30A/m(2)　DC　interference,　the　corrosion　rate　of　X70　steel　increases　significantly.　Therefore,　the　factors　affecting　corrosion　performance　of　X70　pipeline　steel　were　DC＞AC＞stress.　Under　individual　AC　interference,　uniform　corrosion　occurred　on　the　X70　steel　at　an　AC　current　density　of　less　than　30A/m(2),　while　the　pitting　corrosion　occurred　at　an　AC　current　density　of　greater　than　100A/m(2).　The　application　of　tensile　stress　and　DC　had　a　certain　inhibitory　effect　on　pitting　corrosion.