To　simulate　structural　crack　propagation　and　predict　fatigue　life,　the　extended　finite　element　method　(XFEM)　combined　with　the　virtual　crack　closure　technique　(VCCT)　is　adopted　in　this　paper.　Firstly,　the　underlying　principles　of　the　XFEM-VCCT　framework　are　elaborated　comprehensively,　mainly　including　the　calculation　of　crack　tip　energy　release　rate　based　on　VCCT,　the　simulation　of　element　cracking　utilizing　the　phantom　nodes,　and　the　computation　of　structural　responses　under　cyclic　loading　through　the　direct　cyclic　analysis.　In　addition,　to　calculate　the　crack　propagation　length,　an　interpolation　method　to　obtain　the　crack　tip　coordinates　is　developed　based　on　tracking　and　locating　the　crack　by　the　level　set　functions.　Meanwhile,　to　compensate　the　defect　that　the　fatigue　life　is　often　overestimated　when　dealing　with　the　complex　mode　crack　in　complex　structure　through　XFEM-VCCT,　a　simple　improved　algorithm　based　on　the　average　rate　concept　is　proposed　without　altering　the　XFEM-VCCT　framework.　Based　on　specific　examples,　the　necessity　and　accuracy　of　the　improved　algorithm　are　fully　verified　by　comparing　with　the　original　method,　and　the　fatigue　life　predicted　by　the　improved　algorithm　is　more　consistent　with　reality.　Finally,　this　method　is　successfully　applied　to　the　simulation　and　analyses　for　a　typical　ship　stiffened　plate　structure,　demonstrating　good　engineering　applicability.