During the blasting excavation of deep rock mass under high in-situ stress, energy sources of vibration are composed of energy produced by the detonation of explosive and strain energy released by excavated rock mass. The precision of the prediction of vibration peak induced by blasting excavation under high in-situ stress is reduced by using Sodev’s empirical formula and its improved formulas which are based on the charge per delay. On the basis of energy conservation, a model is proposed for predicting the vibration peak by using the method of dimension analysis. By incorporating with blasting field test in the diversion tunnel of Jinping Ⅱ hydropower station, the monitored vibration data of upper part tunnel is used as the learning sample to calibrate the model, and monitored vibration data of lower part tunnel is used as the contrast sample to test the model. Predicted results indicate that the proposed model has a higher fitting correlation coefficient and a lower root mean square error than traditional ones, and thus it can be well used to predict the vibration peak induced by blasting excavation under high in-situ stress.