This　study　used　the　finite　element　analysis　(FEA)　method　to　simulate　and　analyze　the　fatigue　damage　evolution　process　of　stainless　steel　cruciform　welded　joints,　and　further　predicted　the　fatigue　life.　Utilizing　the　characteristics　that　the　wavelet　packet　sub-band　energy　of　acoustic　emission　signals　is　minimally　influenced　by　the　fatigue　load　amplitude,　during　the　monitoring　of　the　damage　evolution　process　under　high-cycle　fatigue　tests,　a　user-defined　progressive　fatigue　damage　subroutine　for　stainless　steel　was　developed　to　simulate　the　stress　field,　fatigue　damage　field,　fatigue　loading　counts,　and　fatigue　crack　propagation.　Considering　the　elastoplastic　characteristics　of　metallic　materials,　a　method　was　proposed　for　determining　the　cracking-controlling　factor,　saying　that　the　magnification　of　the　maximum　principal　stress　relative　to　the　nominal　stress,　and　the　critical　damage　for　judging　elements＇　fatigue　failure　was　also　given.　By　adopting　appropriate　mesh　division　techniques,　corresponding　stress　magnification　factors,　and　suitable　critical　damage,　the　FEA　fatigue　damage　evolution　model　presented　an　accurate　simulation,　exhibiting　an　average　error　of　1.58　%　compared　to　the　experimental　S-N　curve.　The　results　of　this　research　can　provide　strategies　for　the　full-field　fatigue　damage　analysis　and　fatigue　life　prediction　of　welding　details　in　complex　metal　structures.