The invention discloses a method for restraining power anti-tune by shielding a jamming signal at the start time of sudden load change of an electric generator. The method includes the basic steps that as a disturbance signal of power anti-tune is led into a load controller at the start time of the sudden load change of the electric generator and represents the characteristics of being strong at beginning and weak later and rapidly declining, the load controller of a speed adjusting system is modified, the jamming signal is shielded from the start time of the sudden load change of the electric generator to the time when the disturbance signal declines to zero, the disturbance signal does not enter the load controller, and power anti-tune of a turbine is eliminated.