Abstract: The pitting, intergranular and general corrosion test in the nuclear power simulation water on laser welded joint at different welding speeds, as well as stress corrosion cracking (SCC) test in high temperature and high pressure water were carried out. The results indicated that with the increase of welding speed, the passive current and pitting corrosion potential increased. At the same weld joint, the heat affected zone exhibited the best pitting and intergranular corrosion resistance, followed by weld joint, and the weld zone showed the worst performance. SCC at the lowest welding speed easily took place, and the SCC crack generally initiated and propagated from weld root of the HAZ zone.