Discharge　voltage　is　one　of　the　most　important　parameters　affecting　the　rivet　deformation　in　electromagnetic　riveting　process.　Based　on　the　experiments　with　different　riveting　dies,　the　optimal　riveting　die　was　obtained　and　the　effect　of　discharge　voltage　on　the　rivet　deformation　of　TB3　titanium　alloy　was　investigated　from　macroscopic　and　microscopic　aspects.　The　results　show　that　the　riveting　die　has　an　important　effect　on　the　rivet　deformation,　and　the　forming　quality　of　the　rivet　is　determined　by　different　riveting　dies.　When　the　riveting　die　angle　is　50　and　the　discharge　voltage　changes　from　190　V　to　230　V,　the　height　of　the　rivet　head　decreases　and　the　diameter　of　the　rivet　shaft　increases　with　the　larger　discharge　voltage.　The　grains　inside　the　adiabatic　shear　band　are　severely　elongated,　and　the　grains　inside　and　outside　of　the　adiabatic　shear　band　become　more　different.　The　primary　shear　band　inside　the　rivet　head　is　more　and　more　obvious　and　the　width　of　the　shear　band　becomes　smaller　with　the　increasing　of　the　discharge　voltage.　The　deformation　mechanism　of　the　TB3　rivet　is　the　adiabatic　shearing　produced　by　the　deformation　band.