Abstract: Meeting the demand of the H₂S stress corrosion cracking test, the device on the aeration of H₂S for sulfide stress corrosion cracking lab was improved, by the use of automatic switches where H₂S is produced by chemical reaction. This device can aerate H₂S into several experimental vessels at one time. Moreover,the recycle and reuse of hydrogen sulfide discharged at the outlet will become true, so as to decreased the environmental pollution.