The　numerical　prediction　based　on　the　extended　finite　element　method　(XFEM)　is　carried　out　in　this　paper,　where　the　mixed-mode　crack　propagation　process　is　simulated　accurately　and　the　fatigue　life　considering　the　cyclic　overload　effect　is　calculated　conveniently　by　using　the　proposed　novel　method.　In　this　method,　a　simple　crack　surface　updating　strategy　that　can　simulate　the　through-thickness　crack　in　a　three-dimensional　structure　is　proposed,　and　it　replaces　the　complex　level　set　updating　algorithm.　Meanwhile,　the　cycle-by-cycle　method　for　overload　fatigue　life　is　also　proposed.　The　prediction　is　implemented　based　on　the　ABAQUS　software　by　Python　codes　and　the　corresponding　functional　modules　are　developed.　Compared　with　the　built-in　crack　propagation　modules　of　XFEM　in　ABAQUS,　the　method　in　this　paper　contains　the　complete　crack　tip　enhancement　functions　and　presents　strong　robustness　in　computational　convergence　and　excellent　calculation　efficiency.　The　accuracy　in　calculating　stress　intensity　factors　(SIFs)　and　predicting　mixed-mode　crack　growth　paths　is　verified　through　examples.　In　addition,　the　fatigue　life　under　cyclic　overload　is　also　predicted　accurately　by　the　developed　modules.　The　effects　from　different　parameters　of　load　spectrum　with　overload　are　obtained　according　to　the　numerical　results.　Moreover,　combined　with　the　shell-to-solid　coupling　method,　the　large　and　complex　practical　engineering　structure　is　simulated　and　analyzed　in　detail.