Abstract: According to the technical requirement of the grout curtain to prevent the leakage in the foundation of dam, the special apparatus of the jet grouting method has been studied and equipped. In this paper, the technology to construct impervious wall by the jet grouting method is presented.This wall is in contact with the bedrock securely and its thickness is evenly and densely. The working speed is faster and construct cost is less.The set of the technique can be used to construct impervious curtain in the sand and gravelly soil foundation of lowhead dam and cut off wall. The technical parameters which have been obtained can be used to design and construction under suitable conditions.