The invention provides a repairing and strengthening method for a tool of high-temperature in-service shearing equipment. The repairing and strengthening method for the tool of the high-temperature in-service shearing equipment comprises the steps that laser cleaning is conducted on the surface of the tool, and nondestructive testing is conducted, so that a damaged area of the tool is positioned; laser cladding treatment is conducted on the damaged area of the tool, and the damaged area is slightly higher than the surface of the tool after being treated; laser cladding treatment is conducted on the whole surface of the tool, and then polishing treatment is conducted on the whole surface of the tool; the polished surface of the tool is coated with an absorption layer, and laser shocking treatment is conducted on the surface of the tool by penetrating through a restraint layer. By the adoption of the repairing and strengthening method for the tool of the high-temperature in-service shearing equipment, the defects of insufficient repairing and strengthening and the like in the prior art can be overcome, the high-temperature resistance and the abrasion resistance of the tool of the shearing equipment are comprehensively improved, the service life of the tool is greatly prolonged, and practical engineering application problems are solved.