Abstract: Combined with the Xi'longci pumped storage hydroplane project, the several segments having obvious difference in engineering,are simulated by small models based on the three-dimensional FEM and genetic algorithm. The back-analysis parmeters are obtained and input the whole FEM model to compute the displacement around caverns,stress of anchor bar,etc. Matched with observing date, in view of the preceding work, the No.2 excavation is calculated. It calculates successfully the displacement of around caverns, the stability of sum wnding rock, the stress of anchor bar and cable, etc, reveals the stress concentration and potential failure parts of the surrounding rock. It has important directive function.