This paper discusses the optimum design and welding process of the welding line. When the thichness
of the welding line area increases gradually, the strain in this area is coordinative. The improvement of mutual effect between welding line and EB can solve the problem of splash and the quality of welding line corresponds to the standard of GJB 1718A—2005. The mechanical properties of welding line, heat affect zone and raw material are approximately equivalent, the characteristics of the pressure vessel satisfy the design. The optimum design leads the stress of
welding line to decrease, the improvement of welding process increases the quality of welding line, the optimum design of welding line and improvement of welding process is the measure of improvement of welding quality and it is agreat significance of enhancement of pressure vessel performance.