The invention relates to a method for locally tempering a rotor tooth head of a turbogenerator, which is used for tempering a generator rotor whose heating temperature is higher than Ac1 and lower than Ac2. The method has the following beneficial effects that after the technical scheme of the invention is adopted, the temperature and cooling rate of the generator rotor which is abnormally heated can be determined quickly, a correct local tempering process is developed to successfully eliminate the martensite structure at the burnt position and take into account the softened over-tempering zoneas to prevent further over-tempering during tempering from reducing the strength and reduce the thermal impact on the normal matrix, thus avoiding the introduction of large thermal stress on the rotor teeth.