In　order　to　research　the　fatigue　properties　of　ultra-high　strength　steel　welding　spot,　the　22MnB5　spot-welding　structure　was　taken　as　the　research　object.　An　intermediate　frequency　servo　spot-welding　device　was　used　to　weld　the　specimens　with　a　thickness　of　2　mm.　With　the　high-frequency　fatigue　testing　machine,　laser　repair　welding　device　and　optical　microscope,　the　S-N　curves　of　specimens　under　different　welding　process　parameters　were　studied.　The　results　show　that　the　welding　time　and　current　parameters　have　obvious　influence　on　the　fatigue　life　of　welding　spot　in　the　high　stress　area,　while　have　small　influence　on　the　fatigue　life　of　welding　spot　in　the　low　stress　area.　In　addition,　the　reasonable　process　parameters　can　effectively　improve　the　fatigue　life　of　welding　spot.　After　the　repair　welding　for　the　tiny　circumferential　vulnerable　zone　of　welding　spot　with　the　laser　process,　the　structural　strength　of　welding　spot　can　be　effectively　enhanced.　©　2016,　Editorial　Department　of　Journal　of　Shenyang　University　of　Technology.　All　right　reserved.