In　order　to　comprehensively　study　the　effect　of　hydrogen　corrosion　on　the　crack　growth　rate,　45　steel　was　used　as　a　typical　material　in　this　paper　and　fatigue　crack　growth　rate　(FCGR)　of　under　different　corrosion　conditions　and　different　stress　ratios　at　room　temperature　were　tested.　9　groups　of　da/dN-Δ　curves　were　obtained　and　Paris　expressions　were　fitted.　The　results　show　that　under　the　experimental　conditions　of　air　and　different　concentrations　of　H2S　corrosion　environment,　the　value　of　parameter　n　of　Pairs　expression　is　basically　stable　at　3.5.　Under　the　same　stress　ratio　conditions,　the　FCGR　of　metals　after　H2S　corrosion　is　greater　than　that　of　metals　in　the　air　environment,　and　it　increases　with　the　increase　of　corrosion　concentration,　Stress　ratio　affects　FCGR　greatly,　and　the　effect　of　corrosion　time　is　limited.　©　Published　under　licence　by　IOP　Publishing　Ltd.