Abstract: The bogie was the running device of a high-speed train, its performance was with a great effect on running safety, riding comfort and stability for vehicles. Frame was the skeleton of the bogie, it assembled all parts, was used to support and bear transmission torque and load, thus it played an important role in the bogies. As for CRH1 bogie frames, the frame was with all steel welded structure, and easily producing bead cracks, leakage solder, irregular weld shapes and so on. Thus, the surface quality detection for the weld was necessary. This paper firstly analyzed formation reasons of fault welds, and then, adopted the work piece of class bead cracks, class leakage solder, class irregular weld shapes to test and verify welding thermal stress analysis. Finally, effective measures for frame welding strength were proposed to guide the actual production to some extent.