A high-pressure energy-gathering water jet generator was proposed to solve the problems of rock breaking caused by the short target distance and small nozzle diameter, which made it difficult to achieve efficient rock breaking. The device uses the valve core to change the flow direction of the fluid medium so that the piston moves reciprocally in the cylinder, realizes the pressurization effect of the jet by relying on the high-speed movement of the piston, and realizes reliable regulation of the jet pulse frequency and pulse pressure by changing the flow rate of the pump station. Firstly, the whole structure and different working stages of the high-pressure jet generator are introduced in detail, and its working principle is expounded. Secondly, based on fluid mechanics and energy conservation theory, a dynamic model of a high-pressure energy-gathering water jet generator is established to analyze the relationship between different structural parameters and dynamic parameters of the device, explore the influence of device structural parameters on jet impact pressure, and reveal the energy evolution law of a pressurized piston in the impact process. The impact pressure of the jet, the area of the oil outlet, the diameter of the piston rod, the diameter of the nozzle outlet, and the system pressure all increase first and then decrease, and the influence of the system pressure, the nozzle outlet pressure, the area of the oil outlet, and the diameter of the piston rod on the performance of the device decreases successively. On this basis, the high-pressure shaped charge jet rock breaking test system and hydraulic control system are constructed, and the high-pressure shaped charge jet impact rock breaking test research is carried out to verify the feasibility of the system and the correctness of the theoretical analysis. The experimental results show that the high-pressure-shaped jet has a better rock-breaking effect than an ordinary jet, both in terms of crushing depth and crushing pit volume. The rock-breaking process of high-pressure jet impacts changes periodically. Under the input pressure of 10 MPa, the output pressure can reach 72.5 MPa, which has a good pressurization effect. Under the predetermined system pressure, the optimal target distance of a jet-impacting rock is 10 cm. The impact frequency of the jet increases linearly with the flow rate of the hydraulic pump, and the rock crushing volume, crushing pit diameter, and depth all increase with the increase in impact frequency.