Welding　distortion　causes　the　change　of　stress　distribution　of　load-carrying　cruciform　stainless　steel　welded　joints,　and　the　weld　with　angle　less　than　90　degrees　between　steel　plates　became　the　fatigue　performance　control　weld　because　of　stress　magnification.　The　effect　of　angular　misalignment　on　fatigue　performance　of　stainless　steel　cruciform　welded　joint　was　experimentally　and　numerically　studied.　The　fatigue　damage　evolution　equations,　under　different　stress　amplitudes,　were　derived　using　relative　deformation　increment　as　damage　variable　based　on　continuum　damage　mechanics　to　explain　the　process　of　damage　transformation　from　micro　to　macro　crack　and　finally　rapid　fracture.　The　hot　spot　stress　magnification　factor　was　positively　correlated　with　the　welding　distortion　angle　and　exhibited　two　discernible　stages　of　rise　and　fall　with　increasing　nominal　stress　taking　the　proportional　limit　as　boundary.　A　proposed　formula　considering　both　misalignment　angle　and　applied　stress　aimed　to　enhance　accuracy　in　fatigue　performance　evaluation　compared　to　current　methods.　The　fatigue　damage　evolution　process　was　described　by　continuum　damage　mechanics.The　Km　showed　two　stages　of　increase　and　decrease　divided　by　proportional　limit.The　calculation　formula　for　the　hot　spot　stress　magnification　factor　was　suggested.Suggested　method　considering　angular　misalignment　was　more　precise　for　life　prediction.