Stress corrosion crack (SCC) susceptibility of titanium alloy TC4 in methane and hydrochloric acid methane solution was studied by slow strain rate tensile test (SSRT), SEM analysis and metallography observation. The experimental results show that TC4 is possessed of SCC susceptibility in methanol solution, and addition of methanol solution to hydrochloric acid methanol solution can greatly improved the SCC susceptibility of TC4 alloy. SCC of TC4 in hydrochloric acid mdethanol solution originates from the bottom of the corrosion pits.