For the purpose of improving the cleanliness of nozzles for cleaning equipment, the k-kl-w three-equation turbulence model and finite element theory are used to analyze the pressure distribution, velocity distribution and cavitation degree of the three types of micro-nozzles in this paper. The results show that: 1) compared with conical and circular cross-section nozzles, the maximum velocity variation per unit time of the abrupt cross-section nozzle is 224.13 m/s at the neck of the structure, and the abrupt cross-section nozzle is more likely to have the effect of cavitation; 2) the cavitation areas of conical and circular cross-section nozzles are much smaller than that of abrupt cross-section nozzle, and the maximum vapor volume fraction of the two types of nozzles is about 37.5% of that of abrupt cross-section nozzle under the same conditions; 3) the fluid of the abrupt cross-section nozzle is turbulent under high pressure fluid, and the turbulent kinetic energy and turbulent intensity are the largest compared with conical and circular cross-section nozzles; 4) the turbulent kinetic energy and turbulent intensity of the circular cross-section nozzle are almost equal to zero, and the fluid is a laminar flow. The circular cross-section nozzle may maintain better stability of fluid laminar flow compared with abrupt and conical cross-section nozzles. The analysis results of nozzle optimization show that the cavitation strength of nozzles can be significantly enhanced by increasing the nozzle structure of abrupt cross-section.