Abstract: Karst leakage is a key factor constraining the construction of pumped storage power stations in karst areas; due to the complex conditions of karst development, the tment of karst leakage is difficult, necessitating in-depth research.This study investigates the karst development characteristics and karst leakage conditions of the Guizhou Xinshui Karst Pumped Storage Power Station by employing methods of d survey and fracture measurement, hydrogeological exploration, and long-term observation of borehole water levels.Research results indicate that karstification is well-developed in the thick limestone layers of the Permian Maokou Formation (P2m) in the reervoir area, with not only well-developed dissolution fissures, solution pores, and caves, The cave encounter rate and linear karst rate reached 80% and 24.46%, respectively, There are numerous karst caves within 100 meters of the riverbed bottom, and due to the long-term flow of groundwater without significant filling, the reservoir faces a high risk of seepage around the dam and through the dam.It is necessary to take anti-seepage measures for treatment, Karst in the riverbed floor mainly develops within a range of 100 meters, so a seepage prevention treatment depth of 100 metersm foundation is sufficient.The left bank of the river is influenced by the Haiku Syncline and the Chenjiawanzi Fault, resulting in a higher degree of karst development ththe riverbed and the right bank, forming a groundwater level trough zone with conduit char. During the normal and low-water periods, the groundwater level in the low trough zone is 4-5 meters lower than the riverbed water level, and er recharges the groundwater in the low trough zone of the left anticlinal axis in reverse.After the current reservoir water level rises, the seepage into the syncline karst channel on the left bank will be further exacerbated.Reservoir karst leakage pathways are numerous and complex, making leakage prevention difficult; therefore, comprehensive seepage control treatment for the entire reservoir