The　welding　quality　directly　affects　the　intensity　of　spot　welding　components,　but　the　diameter　of　the　nugget　and　welding　heat　affected　zone　and　around　instantaneity　and　the　concealment　of　the　nugget　size,　it　is　difficult　to　detect　the　welding　joint　details　by　conventional　methods.　In　this　context,　the　22MnB5　and　Q235　steel　as　the　research　object,　combined　with　the　engineering　test　and　finite　element　software　ANSYS　as　a　platform,　to　establish　finite　element　model　of　spot　welding.　The　core　part　of　components　model　is　by　nugget,　plastic　ring　(PR)　and　base　metal　of　three　parts,　further　analysis　of　mechanical　properties　of　solder　joints.　Not　only　it　helps　to　further　understand　the　mechanism　of　spot　welding　and　quickly　improves　the　quality　of　spot　welding,　to　guide　the　production　practice　and　to　optimize　spot　welding　process,　to　greatly　reduce　the　cost,　time　and　studied,　but　also　the　actual　production　data　can　be　used　in　the　finite　element　model,　and　can　achieve　good　quality　control.