Research conclusions: By the measure experiment on the spot to compare of impact force between wheel and rail and track structure vibrational acceleration, the results show that effect on impact force between wheel and rail is distinct by irregularity on rail welded joints. Especially when wavelength of the irregularity on track surface at the size is inconsistent , the effects on the P1and P2 are inconsistent as well as. At the same time，it shows that P2 can be reduced distinctly by the improvement of irregularity on rail welded joints,so that stress of track structure can be reduced.