Abstract: In modern risk society, ubiquitous technology risk caused the rise of risk administration not only reshape the new "regulation state", but influence on the modern administrative law. Under this background, according to the essence of the modern public administrative,we need to must integrate value rationality with instrumental rationality in risk regulation. In the article, author takes food safety administrative as example, the research show that administrative process theory which emphasize modern administration is a process of reflection, consultation, negotiation, the selection, in line with the spiritual implication of the modern public administration of open, service, innovation, has strong theoretical explanation ability in risk administration, can provide a theoretical analysis framework for legitimate of risk administration.