The　casing　integrity　problem　presents　severe　challenges　for　shale　gas　wells　regarding　the　multi-stage　fracturing　operation.　Multiple　factors　during　fracturing　process　may　have　individual　or　combined　influence　on　it.　However,　most　of　the　researchers　only　studied　one　fracturing　stage.　The　influence　of　cyclic　fracturing　loading　on　casing　of　shale　gas　well　has　been　rarely　studied.　This　paper　presents　a　finite　element　model　approach　to　simulate　the　multi-stage　fracturing　operations.　Based　on　the　theory　of　elasto-plasticity,　the　nonlinear　isotropic/kinematic　hardening　material　was　used　to　simulate　the　response　of　the　casing　under　cyclic　loading.　The　transient　temperature-pressure　coupling　model　of　casing-cement　sheath-formation　(CCF)　was　established.　Multiple　analysis　steps　were　used　to　simulate　the　multi-stage　fracturing　processes.　The　cement　channel　angle,　pump　rate,　and　fracturing　fluid　temperature　were　the　variables　taken　into　account.　An　attempt　was　made　to　reveal　how　the　factors　affect　the　casing　stress.　Sensitivity　analyses　showed　that　the　cement　channel　had　the　greatest　influence　on　casing　stress.　The　casing　had　the　highest　Von　Mises　stress　and　equivalent　plastic　strain　(PEEQ)　at　the　channel　angle　between　60　degrees　and　90　degrees.　The　stress　could　be　easy　to　exceed　the　casing　yield　stress,　causing　the　casing　failure.　The　more　the　fracturing　stage　was,　the　larger　the　Von　Mises　stress　and　PEEQ　of　casing　were.　Larger　pump　rate　tended　to　dramatically　reduce　the　downhole　temperature.　The　lower　the　temperature　of　the　fracturing　fluid　was,　the　greater　the　reduction　of　the　downhole　temperature　was.　When　the　cement　channel　angle　was　smaller　than　60　degrees,　the　casing　had　the　higher　Von　Mises　stress　and　PEEQ　for　the　larger　pump　rate　and　lower　fracturing　fluid　temperature.　The　results　indicated　that　good　cement　sheath　was　the　basic　requirement　to　ensure　the　safety　of　casing.　The　pump　rate　and　fracturing　fluid　temperature　should　be　in　a　reasonable　range.　During　multi-stage　fracturing　construction,　the　pressure　should　be　not　too　high　to　reduce　the　casing　stress,　avoiding　the　risk　of　casing　deformation.