Abstract: In nuclear power station, reactor is often forced to shut down for mainten-ance due to serious stress corrosion crack of steam generator tube. To study thetendency of steam generator tube to SCC, a type of autoclave device for SCCtest in caustic solution is developed. The container fabricated from Nickel withwelding seal is used for placing caustic solution and material specimens. The con-tainer is put in the autoclave, connceted with autoclave outside with pipe, andfilled in with pure argon at 2-3 kg/cm~2. C-type of specimen is used for SCC test. Incoloy 800 alloy specimens withshot peening and without shot peening are tested in 50% (wt) NaOH solution at300℃, and SCC is observed on specimens without shot peening after 200 h expo-sure to above codition. The results show that this autoclave device is reliable and safe in use, it willbe able to meet the needs of caustic SCC testing of materials for steam generatortube in nuclear power station.