The invention discloses a method for quantizing operation security indexes of a nuclear power station. The method comprises the following steps: acquiring a damage value, to the safe operation of the nuclear power station, of abnormal function data in function data of an operation parameter item of the nuclear power station; acquiring a hidden danger value, to the safe operation of the nuclear power station, of defect equipment of the nuclear power station; according to the damage value, the hidden danger value, the reliability performance value of nuclear power equipment, a man-machine matching value, a security boundary grade of the nuclear power station and an event and accident influence value, by presetting the weighting of each value, quantizing the operation security indexes of the nuclear power station. According to the method for quantizing the operation security indexes of the nuclear power station, disclosed by the invention, by quantizing the operation security indexes of the nuclear power station, more accurate monitoring on the equipment security operation of the nuclear power station is realized; furthermore, the invention also discloses a system for quantizing the operation security indexes of the nuclear power station.