1. Technical Field of the invention defined in the claims The invention relates to a method of heat treatment Fatigue fire. 2. The invention attempts to solve the technical challenges Conventionally, when the metal material is degraded appears the fatigue strength decrease phenomenon, a technique has been desired to improve the fatigue strength of this heat or fire. 3. Resolution of the subject matter of the invention, Used to material that is degraded improve the fatigue strength of the induced heat fire fatigue strength degradation, leading to the generation of compressive residual stress due to the surface hardening layer of martensitic phase transformation, by using a high temperature heat source of the laser beam, and the long-term the segregation in the grain boundary in accordance with impurities is characterized in that to increase the fatigue life by Sikkim diffusion by high-temperature heat source. 4. An important use of the invention, Local treatability, controllability, complex shape of the punctured area, the degradation treatment is possible up to an inaccessible area, also has a great usefulness economical profit for it, enabling the treatment of the deterioration of uninterrupted operation of the machine and structure.