Abstract: After Fukushima nuclear accident in Japan,all the countries in the world are more and more concerning the potential impact of external events on nuclear facilities,including the potential impact of the flood.However,we are lacking of a reasonable flood control standard for nuclear fuel cycle facilities in China currently,which will not only hinder the flood protection for nuclear facilities,but also affect the safety of nuclear facilities directly.Based on the potential risks of nuclear facilities,referring to the existing four classes of nuclear facilities risk classification,considering the importance of nuclear facilities,economic losses and environmental consequences caused by flood,this paper proposes a flood control standard for each risk categories of nuclear facilities.