The S355 J2 + N thick plate commonly used in EMU bogies is taken as the research object,aiming at the defects of the base metal of the thick plate after the completion of bogie frame manufacturing,the performance research after welding repair is carried out. The simulated repair joints are made and the tensile test,bending test,impact test and hardness test are carried out on these joints,and the static strength and fatigue strength test verification are also carried out on the repaired bogie parts. The results show that the performance of the bogie parts after welding repair can fully meet the requirements of the standards,providing theoretical basis for the welding repair operation in actual production.