A device for welding a rail joint of a track, comprising two rail clamping devices spaced from one another in a rail longitudinal direction which are connected to one another via push rods to press rail ends apart prior to welding. In this, it is provided that at least one rail clamping device is coupled to a transverse displacement device for flush-aligning the rail ends after being pressed apart.

A rail welding method and device are provided. The method includes: welding a bottom of rail, wherein welding is repeatedly performed along a first swing trajectory in a lengthwise direction of a weld seam, from one end of the bottom of rail to the other end of the bottom of rail; welding a waist of rail, wherein welding is repeatedly performed in the lengthwise direction of the weld seam along a second swing trajectory, from one end of the waist of rail, and the second swing trajectory is divided into two regions for respective welding in a width direction of the weld seam; and welding a head of rail, wherein welding is performed in the lengthwise direction of the weld seam along the first swing trajectory, between one end of the head of rail and the other end of the head of rail.