The invention discloses a stainless steel or nickel sheet laser tailor-welding alignment clamping device and a method. The alignment clamping device comprises an XYZ three-dimensional translation RZ one-dimensional rotation motion mechanism, a video monitoring alignment regulating mechanism and a magnet pneumatic clamping mechanism, wherein the stainless steel or nickel sheet laser tailor-weldingalignment clamping device can align and position sheets through the XYZ three-dimensional translation RZ one-dimensional rotation motion mechanism and the video monitoring alignment regulating mechanism, and then clamps and fixes the stainless steel or nickel sheets by the magnet pneumatic clamping mechanism to realize the laser tailor-welding of the stainless steel or nickel sheets. The invention can solve the problem of difficult welding of the stainless steel or nickel sheets smaller than 0.3mm in thickness in laser butt welding because the sheets are easy to deform owing to easy deformation property per se and thermal stress, and guarantees the quality of tailor-welded seams.