Method and device for repairing surface of large metal part through destressing laser impact forging

The invention discloses a method and a device for repairing the surface of a large metal part through destressing laser impact forging. The surface of the large metal part is repaired by adopting a compound machining technology method that double light beams work simultaneously. A first beam of continuous laser conducts repairing on the to-be-repaired large metal part by utilizing hot-effect molten metal powder, and meanwhile a second beam of short-pulse laser conducts synchronous impact forging on a material in a cladding area in a plasticity deformation temperature zone at the optimal temperature simultaneously by using a shock wave mechanical effect. Finally, the defects of gas holes on a repairing layer of the large metal part and poor compactness are overcome, the internal stress is eliminated, and the comprehensive mechanical property of the large metal part is improved.