The invention relates to a method for connecting thick-walled metal workpieces by welding. In order to create the weld joint, the cross-sections are provided with a maximum of three weld regions according to wall thickness, the welding being carried out by a combined use of welding methods: the first weld region (root) is welded by means of laser beam welding or hybrid laser-arc welding, the second weld region is welded by means of hybrid laser-arc welding, and the third weld region required occasionally depending on the thickness of the sheet metal is welded by means of hybrid laser-arc welding or simply arc welding. The invention also relates to a seam preparation corresponding to the respective welding method used.