Abstract: The Danjiangkou Reservoir is not a reliable stable base for water source,the Yellow River flow is frequently cut out and the Weihe River has lack of water. These problems can not be solved in present scheme of the East and Middle lines of S-N water diversion, but can be solved in the new line scheme, which is of great benefit. This paper deals with geology and engineering-geological condition of the new line. No technical and geological problems can not be solved in implementation of this line scheme.