Abstract: The high-pressure nozzle is an important component in the high-pressure water jet cleaning system, and the structure of the nozzle directly affects the effectiveness of high-pressure water jet cleaning, Therefore, the research on high-pressure nozzles is of great significance. This article conducts structural design, model establishment, numerical simulation, and result analysis of high-pressure nozzles. The target impact pressure and jet velocity are important analytical parameters, and the impact of different nozzle structures and target distances on the dynamic performance of ultra-high pressure water jets is analyzed. The optimal high-pressure nozzle structure and the most reasonable impact distance are obtained. The results show that the jet velocity of the tapered nozzle is 4.2% higher than that of the conical nozzle and 1.6% higher than that of the streamlined nozzle. When the impact target distance of the tapered nozzle decreases from 50.68 mm to 10 mm, the average dynamic pressure value of the jet greater than 10 MPa increases from 27.2 MPa to 31.9 MPa, and the average dynamic pressure value of the jet greater than 40 MPa increases from 47.9 MPa to 66.9 MPa; When the corresponding target distance is 20 mm, the effective impact area greater than 10 MPa is maximum, reaching 8.3 cm².