Mechanical　parameters　of　spot-welded　structure　of　22MnB5　ultra-high　strength　steel　were　obtained　by　a　series　of　experiments　including　tensile-shear　testing,　optical　experiment　and　the　vickers-hardness　testing.　In　addition,　intensity　simulations　on　the　spot-welded　structure　were　carried　out　by　software　ANSYS.　The　good　agreement　of　simulation　results　with　experimental　data　confirmed　the　rationality　of　the　three-phrase　finite　element　model　of　the　spot-welded　structure,　which　consist　of　weld　nugget,　plastic　ring　and　base　metal.　Based　on　the　simulation　results,　the　plastic　ring　edge　of　the　spot-welded　structure　interface　is　the　weakest　position,　where　the　structural　failure　is　mainly　caused　by　the　shear　stress.　For　purpose　of　spot-welded　structure　optimization,　the　dependence　of　strength　of　the　spot-welded　structures　on　their　structure　parameters　were　analyzed.　The　simulations　results　uncovered　that　the　maximum　Von　Mises　stress　of　the　structure　can　be　reduced　to　a　considerable　extent　by　increasing　radius　of　the　weld　nugget,　the　overlapping　length　of　the　two　sheets　and　the　thickness　of　the　plates.