An excimer laser annealing device, comprising an optical compensation system for a laser beam, wherein the optical compensation system for the laser beam comprises a laser source, a beam splitter and a reversion assembly, the laser beam emitted by the laser source enters the beam splitter, and is divided by the beam splitter into a first light beam and a second light beam having different transmission paths, and the second light beam is reversed and reflected by the reversion assembly, enters the beam splitter, and exits from the beam splitter together with the first light beam,
- wherein an asymmetry of the second light beam reversed by the reversion assembly is different from an asymmetry of the first light beam.