Aluminum profiles are widely used in the manufacture of high-speed train body,the researh was made of the residual stress,the distribution and residual stress reduction of the key parts of the bolster. Ultrasonic is adopted to eliminate stress on the simulation part,using blind hole method to measure the size of welding residual stress before and after impact,tensile,bending,fatigue test were carried out after the impact of the parts sampling. The results showed that:ultrasonic impact treatment for reducing weld and HAZ high stress zone;as the current increasing,residual stress elimination rate increases accordingly,when the current is 1.6 A,the reducing rate is 33%,the homogenization rate is 44%,welded joint tensile,bending and fatigue performances meet the requirements.