In order to ensure water supply for reservoir area afforestation and irrigation of farmland and forestry,and to improve the impervious performance of the reservoir,the high-pressure jet grouting cut-off wall of Nianwanping Reservoir was constructed.Based on the test,the construction with three-pipe grouting was adopted.In the paper,application of high-pressure jet grouting cut-off wall construction technology,including construction procedure,specific cases treatment,quality control,and water filling for seepage detection are analyzed.It provides reference for construction quality control of high-pressure rotary jet cut-off wall.