Through the optimization research of the lubricating oils of rotating mechanical equipment of a nuclear power plant，an optimization method that is applicable to the lubricating oils of rotating mechanical equipment of nuclear power plants was summed up.This method realized the streamlined management of lubricating oils,the scientific optimization of lubricating oils and the integrity of lubricating oil optimization technical specification.This optimization method was applied to a new nuclear power plant,and the requirement was realized to reduce the types and grades of lubricating oils.Thereby,the purchasing and storage costs of lubricating oils are effectively reduced,and the standardization of lubricating oil management in nuclear power plants is improved.