Shear　deformation　often　occurs　during　multistage　fracturing　of　shale　gas　worldwide,　increasing　the　operation　cost　of　gas　well　completion　and　lowering　the　well＇s　productivity;　strike-slip　fault　slippage　is　thought　to　be　a　crucial　underlying　factor.　This　paper　presents　a　detailed　analysis　of　the　influence　of　strike-slip　fault　slippage　on　casing　inner　diameter　and　establishes　a　technique　for　predicting　casing　inner　diameter　after　fault　slippage.　Numerical　simulation　models　were　developed　to　simulate　the　process　of　fault　slippage　and　calculate　changes　in　the　inner　diameters　of　the　casing,　considering　different　engineering　and　geological　conditions.　The　influential　factors,　including　the　fault　strike　angle,　slip　distance,　radius-thickness　ratio,　and　mechanical　properties　of　the　formation,　were　analyzed　in　engineering　practice;　the　simulation　results　were　shown　to　be　consistent.　Four　methods,　including　adjusting　the　wellbore　trajectory　of　shale　gas　horizontal　wells,　avoiding　perforation　at　the　formation　interface,　decreasing　the　fracturing　parameters　including　the　fracturing　pressure,　discharge　capacity,　volume　of　injecting　fracturing　fluid,　and　prediction　of　casing　inner　diameter　after　casing　shear　deformation,　were　proposed　and　verified　through　engineering　application　and　theoretical　calculation,　respectively.　(C)Y　2021　The　Authors.　Published　by　Elsevier　Ltd.