Abstract: In the method of drawing fiber continuously from preforms for manufacturing an optical fiber, a first preform is displaced along a fiber-drawing axis and is drawn into an optical fiber through a fiber-drawing furnace disposed on the fiber-drawing axis, and a second preform is displaced along the fiber-drawing axis, which second preform is butt welded to the first preform so as to be drawn into an optical fiber following on from the first fiber. The two preforms are butt welded, i.e. they are welded together end-to-end, by displacing at least one power laser along the fiber-drawing axis, and by servo-controlling the displacement of said laser to the displacement of the two preforms so as to maintain a laser beam emitted by the power laser at the same height as the two ends to be welded together, thereby making it possible to reduce considerably the size of the zone affected by the welding, and to avoid polluting the side surfaces of the two preforms upstream and downstream from the weld.