Abstract: Flash butt welding ( FBW ) is widely used in rail welding because of its high efficiency and excellent characteristics. However, there are still some problems in the welded joints, such as gray spot defects and weld decarburization, which can not be completely solved. To address this problem, flash-friction hybrid welding (F-FHW) has been developed. In this paper, U71Mn steel was welded by flash-friction hybrid welding, and compared with flash welding, and the influence laws of the two welding methods on the microstructure, temperature field and properties were studied. The results indicate that the weld of F-FHW welding can obtain a metal microstructure close to that of the base metal; the grain size in the weld of the FBW is grade 1, while that of the F-FHW is grade 2.5. The high temperature of the FBW welding is concentrated in the central area, and the distribution of the high temperature zone in the F-FHW welding temperature field is more uniform; The hardness of FBW shows a significant decrease and is slightly lower than that of the base material, while the hardness distribution of F-FHW joints is uniform and higher than that of the base material. The impact fracture morphology of the FBW was deconstructed with a few tough spots and a few gray spots were found, while the impact fracture morphology of the F-FHW weld was deconstructed and no gray spots were found.