Abstract: The digital constant temperature water-bath HH-4 was used to simulate the pit corrosion test method to study pit corrosion of 316L austenitic stainless steel welding seam in different Cl- density and the different temperature,in FeCl3 solution corrosion behavior,the effect of Cl- density and the temperature variation on the material performance to resist pit corrosion were discussed. The test result showed that in FeCl3 solution,as the Cl- density and temperature increasing,316L pit corrosion resistant property declined respectively,corrosion rate rised,the corroded feature was non-uniform pit corrosion.