Long　distance　pipeline　transmission　is　considered　to　be　the　most　economic　and　safest　method　to　transport　natural　gas　in　recent　days.　The　pipeline　safety　problem　is　a　focus　of　concern　in　the　academic　and　industrial　circles.　Wildly　used　material　X70　pipeline　steel　is　tested　in　this　paper.　Based　on　actual　conditions　of　long　distance　pipeline,　experiments　were　designed　by　using　orthogonal　method.　Corrosion　fatigue　crack　growth　tests　were　carried　out　under　different　H2S　concentrations　(2000　ppm,　1000　ppm,　500　ppm),　stress　ratios　(0.9,　0.8,　0.7),　and　load　frequencies　(0.0067　Hz,　0.01　Hz,　0.013　Hz).　A　phenomenological　model　was　built　based　on　test　data　and　Paris　formula,　which　corrects　parameters　C　and　n　of　the　Paris　formula　at　the　same　time.　The　boundary　element　method　(BEM)　was　used　to　simulate　the　process　of　corrosion　fatigue　crack　propagation.　Fatigue　crack　growth　rates　(FCGRs)　under　different　loading　conditions　were　obtained　and　all　the　parameters　of　the　phenomenological　model　were　calculated　from　test　data.　Compared　with　traditional　Paris　formula,　this　new　model　shows　coupling　interactions　of　stress　ratio,　load　frequency,　and　H2S　concentration　to　both　slope　and　intercept　of　FCGR　curve　in　log-log　space.　The　simulation　results　show　that　the　largest　difference　between　actual　test　data　and　BEM　simulation　is　less　than　10%.　According　to　the　analysis　of　coupling　interactions　of　each　factor,　the　slope　of　fatigue　crack　growth　rate　(FCGR)　curve　in　log-log　space　is　mainly　influenced　by　frequency;　the　influence　of　H2S　concentration　is　nonlinear,　and　FCGR　increases　significantly　with　the　increase　of　stress　ratio　and　decrease　of　frequency.　The　BEM　is　suitable　to　be　used　in　the　engineering　field　to　predict　the　residual　life　of　pipelines.