A system for controlling a generator rotor locking pin, comprising a fixed locking pin and a rotor formed with a locking hole, and further comprising a detection reference component synchronously rotating with the rotor and formed with a detection hole, the detection hole radially corresponding to the locking hole; an optical quantity detection component fixed with respect to the rotor; and a control component configured to output a first control instruction to a rotor driving component according to a position signal of the detection hole obtained by the optical quantity detection component. The detection hole is used as an object to be detected, so that the circumferential relative position relationship of the locking hole with respect to the locking pin can be accurately determined, to output the first control instruction to the rotor driving component, thereby accurately centering the locking pin and the locking hole along with the rotation of the rotor. Moreover, in addition to obtaining an accurate centering precision, this solution greatly increases the centering efficiency. On this basis, the present invention further provides a method for controlling a generator rotor locking pin.