Hebei Zhangjiakou City's artificial reservoir project, covering an area of 1,600,000 square meters and a capacity of 90,000,000 cubic meters. The seepage prevention system uses 200g/1.0mm/200g filament composite membrane. After the seepage prevention construction is completed, an integrity test of the seepage prevention layer is conducted on-site using the double-electrode detection method. Thirty leakage points were found, mostly due to mechanical rolling damage. The leakage points were repaired and re-measured to meet the standards.