Abstract: Flash butt welding on the application of weathering steel for transmission tower were studied in the paper. Flash butt welding is heated by short circuit of welding section, and dynamic recrystallization on the interface forms weld during the loading and forging deformation process. After annealing of weldment, pearlite + ferrite microstructure of weld and heat affected zone was similar to that of base metal, and mechanical properties of welded samples were consistent with those of base metal. Flash butt welding of weathering steel did not need to introduce other welding materials to ensure that chemical composition of weld and base metal was the same, and the difference of microstructure between weld and base metal could be eliminated by heat treatment, and consistency of mechanical properties between weld and base metal could be obtained. For the application of non-coating metallic towers of weathering steel, on one side, flash butt welding ensured stability of mechanical properties of weldment. On the other side, it avoided large potential difference between weld and base metal due to difference in microstructure and chemical composition that led to electrochemical corrosion in the natural environment. Thus, it could meet requirements of non-coating service performance of weathering steel welded components.