Abstract:The drop between upper and lower reservoirs of a pumped-storage power station is large, and the water head is high. The monitoring and prediction of mountain groundwater level change along the water conveyance system is of great significance to safe operation monitoring of the power station. In order to predict mountain groundwater level during construction period, environmental monitoring data were obtained through the environmental monitoring station. By combining PCA (Principal Component Analysis) and GA (Genetic Algorithm) to optimize the BP neural network method, a PCA-GA-BP optimization model was established for groundwater level prediction. One pumpedstorage power station in Guangdong is selected, and its environmental factors and mountain groundwater well data along the water delivery system are used. The optimized algorithm model is verified on the basis of analyzing measuring points, layout of the measuring station and impact factors of the groundwater level. The results show that the optimized model has high prediction accuracy, low comprehensive relative error and high determination coefficient in high, medium and low water level prediction, which is better than the single BP prediction model. And the network topology is simpler than the PCA method, which improves comprehensive prediction accuracy and thus has a better prediction performance. In practice, the optimized model can provide reference for safety analysis, engineering early warning and other fields.