Shale　gas　exploration　and　development　maintained　good　momentum,　but　it　has　some　problems　at　the　same　time　urgently　need　to　be　solved,　such　as　sustained　casing　pressure　(SCP),　which　brought　a　lot　of　safety　issues　and　shortened　the　well　service　lifetime.　A　series　of　experimental　investigations　and　numerical　studies　were　carried　out　to　analyze　the　development　of　the　micro-annulus　width　of　the　second　interface　in　the　casing-cement　sheath-formation　assembly　before　and　after　using　the　pre-stressed　cementing　technology.　Triaxial　compression　tests　computed　tomography　scanning　and　accumulated　plastic　strain　tests　were　conducted　to　evaluate　the　residual　strain　under　the　combined　action　of　cyclic　loading-unloading　and　confining　pressure.　Full-size　cement　sheath　experiments　were　performed　to　quantify　the　width　critical　value　of　the　micro-annulus　when　gas　leakage　began　during　multistage　fracturing.　The　corresponding　numerical　models　of　the　full-size　cement　sheath　physical　simulation　facility　and　pre-stressed　cementing　technology　of　a　real　deep　shale　gas　well　were　developed.　Different　combinations　of　factors　were　analyzed　to　quantify　the　variation　of　micro-annulus　and　tolerance　ability　of　fracturing　section　numbers.　The　influence　of　a　series　of　factors,　including　casing　inner　pressure,　pre-stressed　loading,　and　mechanical　parameters　of　the　cement　sheath,　were　analyzed.　The　result　of　the　research　showed　that　the　reduction　of　casing　pressure　and　increase　of　pre-stressed　loading　could　help　to　maintain　the　seal　integrity　of　the　cement　sheath.　Micro-annulus　risks　can　be　reduced　through　lowering　elasticity　modulus　and　raising　Poisson＇s　ratio.　Eight　deep　horizontal　shale　gas　wells　were　cemented　with　pre-stressed　loading.　The　practical　application　results　showed　there　was　no　SCP　in　prior　and　post-multi-stage　fracturing,　which　proved　the　effectiveness　of　this　method.