Abstract: Aiming at the structural characteristics and site conditions of the flexible vertical anti-seepage curtain, an improved method and device for the damage detection of the flexible vertical anti-seepage curtain HDPE laying process are put forward by referring to the dipole method of the horizontal liner system. When a high-voltage direct current is applied on both sides the HDPE vertical membrane, the dielectric potential in the vicinity the hole will show a significant anomaly of potential, which can be detected by measuring the potential location of the leak. Based on the experimental data, the results of simulation test are verified. Finally, the feasibility and influencing factors of cable leakage method in flexible vertical barrier curtain leakage are discussed based on the validated data. The main conclusions are as cable type method can locate the position of the hole by detecting the abnormal point (minimum point) of the surface potential of the HDPE film. It can locate the fault with the accuracy of 0.1 m or less, and the effective detection distance is more than 1 m.The shorter of the distance from the electrode to the HDPE geomembrane or the distance from the sensors to the HDPE geomembrane, the more obvious the vulnerability signal is, the easier it is to determine the vulnerability and its location. The shorter the sensor spacing is, the more obvious the vulnerability signal is, the easier it is to detect the hole and its location, and the smaller the distance from the actual leak point is.