In order to deeply study the mechanical mechanism and construction technology of "coring + splitting" rock breaking in hard rock tunnel under the condition of explosion-proof, drawing on the Water Quality Assurance Project of Tiegang-Shiyan Reservoir in Shenzhen, and grounded in the theory of empty hole effect, the numerical simulation analysis of drilling methods with different empty hole angles and empty hole numbers was carried out to study the influence of crack propagation and splitting pressure. The static blasting empty hole parameters with empty hole angle of 40° and empty hole number of 2 were proposed and applied to the field test. The results show that the smaller the horizontal angle between the splitting hole and the center of the empty hole is, the more helpful it is to the directional propagation of the rock crack, and the ideal angle should be less than 45°. The number of hollow holes plays a role in promoting the rock breaking process of rock. With the gradual increase of the number of hollow holes, the maximum splitting pressure of rock decreases continuously, and the decrease rate of splitting pressure increases gradually. Through experiments, the feasibility of "coring + splitting" rock breaking can be proved. The existence of empty holes helps to form a coherent main crack in the direction of the connection between the empty hole and the splitting hole, thus improving the crushing efficiency of hard rock. The experimental results are basically consistent with the theoretical analysis and numerical simulation results, and the expected rock breaking effect is achieved, which provides a reference for the rock breaking of hard rock under the condition of no blasting.